diff --git a/code/__DEFINES/dcs/signals/signals.dm b/code/__DEFINES/dcs/signals/signals.dm
index a8b1decc85325..c6bfe47ffbf81 100644
--- a/code/__DEFINES/dcs/signals/signals.dm
+++ b/code/__DEFINES/dcs/signals/signals.dm
@@ -729,6 +729,11 @@
 
 #define COMSIG_XENOMORPH_LEAP_BUMP "xenomorph_leap_bump" //from /mob/living/carbon/xenomorph/bump
 
+// Xeno upgrade chambers
+#define COMSIG_UPGRADE_CHAMBER_SURVIVAL "upgrade_chamber_survival"
+#define COMSIG_UPGRADE_CHAMBER_ATTACK "upgrade_chamber_attack"
+#define COMSIG_UPGRADE_CHAMBER_UTILITY "upgrade_chamber_utility"
+
 //human signals
 #define COMSIG_CLICK_QUICKEQUIP "click_quickequip"
 
diff --git a/code/__DEFINES/mobs.dm b/code/__DEFINES/mobs.dm
index 0cd074464345b..38fb91e269d6e 100644
--- a/code/__DEFINES/mobs.dm
+++ b/code/__DEFINES/mobs.dm
@@ -589,12 +589,13 @@ GLOBAL_LIST_INIT(layers_to_offset, list(
 #define CASTE_STAGGER_RESISTANT (1<<15) //Resistant to some forms of stagger, such as projectiles
 #define CASTE_HAS_WOUND_MASK (1<<16) //uses an alpha mask for wounded states
 #define CASTE_EXCLUDE_STRAINS (1<<17) // denotes castes/basetypes that should be excluded from being evoable as a strain
+#define CASTE_NO_MUTATION (1<<18) // Xenos are excluded from getting any mutations.
 
 // Xeno defines that affect evolution, considering making a new var for these
-#define CASTE_LEADER_TYPE (1<<16) //Whether we are a leader type caste, such as the queen, shrike or ?king?, and is affected by queen ban and playtime restrictions
-#define CASTE_CANNOT_EVOLVE_IN_CAPTIVITY (1<<17) //Whether we cannot evolve in the research lab
-#define CASTE_REQUIRES_FREE_TILE (1<<18) //Whether we require a free tile to evolve
-#define CASTE_INSTANT_EVOLUTION (1<<19) //Whether we require no evolution progress to evolve to this caste
+#define CASTE_LEADER_TYPE (1<<19) //Whether we are a leader type caste, such as the queen, shrike or ?king?, and is affected by queen ban and playtime restrictions
+#define CASTE_CANNOT_EVOLVE_IN_CAPTIVITY (1<<20) //Whether we cannot evolve in the research lab
+#define CASTE_REQUIRES_FREE_TILE (1<<21) //Whether we require a free tile to evolve
+#define CASTE_INSTANT_EVOLUTION (1<<22) //Whether we require no evolution progress to evolve to this caste
 
 #define CASTE_CAN_HOLD_FACEHUGGERS (1<<0)
 #define CASTE_CAN_BE_QUEEN_HEALED (1<<1)
diff --git a/code/__DEFINES/mode.dm b/code/__DEFINES/mode.dm
index ac92848b50f90..7b7c4bea09346 100644
--- a/code/__DEFINES/mode.dm
+++ b/code/__DEFINES/mode.dm
@@ -50,6 +50,7 @@
 #define MODE_ALLOW_XENO_QUICKBUILD (1<<14)
 #define MODE_DISALLOW_RAILGUN (1<<15)
 #define MODE_FORCE_CUSTOMSQUAD_UI (1<<16)
+#define MODE_BIOMASS_POINTS (1<<17)
 
 #define MODE_INFESTATION_X_MAJOR "Xenomorph Major Victory"
 #define MODE_INFESTATION_M_MAJOR "Marine Major Victory"
diff --git a/code/__DEFINES/movespeed_modification.dm b/code/__DEFINES/movespeed_modification.dm
index b8e4deeb20b35..b72ed7d134eae 100644
--- a/code/__DEFINES/movespeed_modification.dm
+++ b/code/__DEFINES/movespeed_modification.dm
@@ -32,6 +32,7 @@
 #define MOVESPEED_ID_WARLOCK_CHANNELING "WARLOCK_CHANNELING"
 #define MOVESPEED_ID_XENO_DREAD "DREADXENO"
 #define MOVESPEED_ID_BEHEMOTH_PRIMAL_WRATH "BEHEMOTH_PRIMAL_WRATH"
+#define MOVESPEED_ID_CELERITY_BUFF "UPGRADE_CHAMBER_CELERITY_BUFF"
 #define MOVESPEED_ID_PRAETORIAN_DANCER_DODGE_SPEED "PRAETORIAN_DANCER_DODGE_SPEED"
 
 #define MOVESPEED_ID_SIMPLEMOB_VARSPEED "SIMPLEMOB_VARSPEED_MODIFIER"
diff --git a/code/__DEFINES/status_effects.dm b/code/__DEFINES/status_effects.dm
index 64fb57c8ba1af..961f191cfc0c6 100644
--- a/code/__DEFINES/status_effects.dm
+++ b/code/__DEFINES/status_effects.dm
@@ -39,6 +39,24 @@
 
 #define STATUS_EFFECT_DRAIN_SURGE /datum/status_effect/drain_surge
 
+#define STATUS_EFFECT_UPGRADE_CARAPACE /datum/status_effect/mutation_upgrade/carapace
+
+#define STATUS_EFFECT_UPGRADE_REGENERATION /datum/status_effect/mutation_upgrade/regeneration
+
+#define STATUS_EFFECT_UPGRADE_VAMPIRISM /datum/status_effect/mutation_upgrade/vampirism
+
+#define STATUS_EFFECT_UPGRADE_CELERITY /datum/status_effect/mutation_upgrade/celerity
+
+#define STATUS_EFFECT_UPGRADE_ADRENALINE /datum/status_effect/mutation_upgrade/adrenaline
+
+#define STATUS_EFFECT_UPGRADE_CRUSH /datum/status_effect/mutation_upgrade/crush
+
+#define STATUS_EFFECT_UPGRADE_FOCUS /datum/status_effect/mutation_upgrade/focus
+
+#define STATUS_EFFECT_UPGRADE_PHERO /datum/status_effect/mutation_upgrade/pheromones
+
+#define STATUS_EFFECT_UPGRADE_CAMOUFLAGE /datum/status_effect/mutation_upgrade/camouflage
+
 #define STATUS_EFFECT_MINDMEND /datum/status_effect/mindmeld
 
 #define STATUS_EFFECT_REKNIT_FORM /datum/status_effect/reknit_form
diff --git a/code/__DEFINES/traits.dm b/code/__DEFINES/traits.dm
index 856b0b64d65fc..817045e3e490f 100644
--- a/code/__DEFINES/traits.dm
+++ b/code/__DEFINES/traits.dm
@@ -80,6 +80,7 @@
 #define SPECIES_TRAIT "species" // /datum/species innate trait
 #define CRYOPOD_TRAIT "cryopod"
 #define XENO_TRAIT "xeno"
+#define XENO_BUFF_TRAIT "xenobuff"
 #define ARMOR_TRAIT "armor"
 #define STAT_TRAIT "stat"
 #define NECKGRAB_TRAIT "neckgrab"
@@ -187,7 +188,8 @@
 #define TRAIT_TANK_DESANT "tank_desant"
 ///Builds things better
 #define TRAIT_SUPERIOR_BUILDER "superior_builder"
-
+/// Does not ping tactical sensor
+#define TRAIT_TACTICAL_SENSOR_IMMUNE "tactical_sensor_immune"
 
 /// Prevents usage of manipulation appendages (picking, holding or using items, manipulating storage).
 #define TRAIT_HANDS_BLOCKED "handsblocked"
diff --git a/code/__DEFINES/xeno.dm b/code/__DEFINES/xeno.dm
index 87a0bec6b1ff7..458b0f832203c 100644
--- a/code/__DEFINES/xeno.dm
+++ b/code/__DEFINES/xeno.dm
@@ -92,6 +92,14 @@ GLOBAL_LIST_INIT(defiler_toxin_type_list, list(
 	/datum/reagent/toxin/xeno_ozelomelyn,
 ))
 
+//List of Defiler toxin images
+GLOBAL_LIST_INIT(defiler_toxin_images_list, list(
+	DEFILER_OZELOMELYN = image('icons/Xeno/actions/defiler.dmi', icon_state = DEFILER_OZELOMELYN),
+	DEFILER_HEMODILE = image('icons/Xeno/actions/defiler.dmi', icon_state = DEFILER_HEMODILE),
+	DEFILER_TRANSVITOX = image('icons/Xeno/actions/defiler.dmi', icon_state = DEFILER_TRANSVITOX),
+	DEFILER_NEUROTOXIN = image('icons/Xeno/actions/defiler.dmi', icon_state = DEFILER_NEUROTOXIN)
+))
+
 //List of toxins improving defile's damage
 GLOBAL_LIST_INIT(defiler_toxins_typecache_list, typecacheof(list(
 	/datum/reagent/toxin/xeno_ozelomelyn,
@@ -210,3 +218,31 @@ GLOBAL_LIST_INIT(xeno_ai_spawnable, list(
 
 /// Life runs every 2 seconds, but we don't want to multiply all healing by 2 due to seconds_per_tick
 #define XENO_PER_SECOND_LIFE_MOD 0.5
+
+// Mutations
+GLOBAL_DATUM_INIT(mutation_selector, /datum/mutation_datum, new)
+
+GLOBAL_LIST_INIT(mutation_upgrades_buyable, list(
+	/datum/mutation_upgrade/survival/carapace,
+	/datum/mutation_upgrade/survival/regeneration,
+	/datum/mutation_upgrade/survival/vampirism,
+	/datum/mutation_upgrade/attack/celerity,
+	/datum/mutation_upgrade/attack/adrenaline,
+	/datum/mutation_upgrade/attack/crush,
+	/datum/mutation_upgrade/utility/focus,
+	/datum/mutation_upgrade/utility/pheromones,
+	/datum/mutation_upgrade/utility/camouflage
+))
+
+#define MUTATION_CATEGORY_SURVIVAL "Survival"
+#define MUTATION_CATEGORY_ATTACK "Attack"
+#define MUTATION_CATEGORY_UTILITY "Utility"
+
+#define MUTATION_STRUCTURE_CHAMBER "shell"
+#define MUTATION_STRUCTURE_SPUR "spur"
+#define MUTATION_STRUCTURE_VEIL "veil"
+
+#define	XENO_UPGRADE_BIOMASS_COST_T1 15
+#define	XENO_UPGRADE_BIOMASS_COST_T2 20
+#define	XENO_UPGRADE_BIOMASS_COST_T3 25
+#define	XENO_UPGRADE_BIOMASS_COST_T4 30
diff --git a/code/controllers/subsystem/points.dm b/code/controllers/subsystem/points.dm
index a5b4bb0903c8e..3f50c567b5e93 100644
--- a/code/controllers/subsystem/points.dm
+++ b/code/controllers/subsystem/points.dm
@@ -16,6 +16,8 @@ SUBSYSTEM_DEF(points)
 	var/list/xeno_strategic_points_by_hive = list()
 	///Assoc list of xeno tactical points: xeno_tactical_points_by_hive["hivenum"]
 	var/list/xeno_tactical_points_by_hive = list()
+	///Assoc list of xeno biomass points: xeno_biomass_points_by_hive["hivenum"]
+	var/list/xeno_biomass_points_by_hive = list()
 
 	var/ordernum = 1					//order number given to next order
 
@@ -92,6 +94,13 @@ SUBSYSTEM_DEF(points)
 		return
 	xeno_tactical_points_by_hive[hivenumber] += amount
 
+
+///Add amount of tactical psy points to the selected hive only if the gamemode support biomass
+/datum/controller/subsystem/points/proc/add_biomass_points(hivenumber, amount)
+	if(!CHECK_BITFIELD(SSticker.mode.round_type_flags, MODE_BIOMASS_POINTS))
+		return
+	xeno_biomass_points_by_hive[hivenumber] = clamp(xeno_biomass_points_by_hive[hivenumber] + amount, 0, 500)
+
 /datum/controller/subsystem/points/proc/approve_request(datum/supply_order/O, mob/living/user)
 	var/cost = 0
 	for(var/i in O.pack)
diff --git a/code/datums/gamemodes/nuclear_war.dm b/code/datums/gamemodes/nuclear_war.dm
index 2ddbee953f332..f69493f783728 100644
--- a/code/datums/gamemodes/nuclear_war.dm
+++ b/code/datums/gamemodes/nuclear_war.dm
@@ -2,7 +2,7 @@
 	name = "Nuclear War"
 	config_tag = "Nuclear War"
 	silo_scaling = 2
-	round_type_flags = MODE_INFESTATION|MODE_LATE_OPENING_SHUTTER_TIMER|MODE_XENO_RULER|MODE_PSY_POINTS|MODE_PSY_POINTS_ADVANCED|MODE_DEAD_GRAB_FORBIDDEN|MODE_HIJACK_POSSIBLE|MODE_SILO_RESPAWN|MODE_SILOS_SPAWN_MINIONS|MODE_ALLOW_XENO_QUICKBUILD|MODE_FORCE_CUSTOMSQUAD_UI
+	round_type_flags = MODE_INFESTATION|MODE_LATE_OPENING_SHUTTER_TIMER|MODE_XENO_RULER|MODE_PSY_POINTS|MODE_PSY_POINTS_ADVANCED|MODE_DEAD_GRAB_FORBIDDEN|MODE_HIJACK_POSSIBLE|MODE_SILO_RESPAWN|MODE_SILOS_SPAWN_MINIONS|MODE_ALLOW_XENO_QUICKBUILD|MODE_FORCE_CUSTOMSQUAD_UI|MODE_BIOMASS_POINTS
 	xeno_abilities_flags = ABILITY_NUCLEARWAR
 	valid_job_types = list(
 		/datum/job/terragov/command/captain = 1,
diff --git a/code/datums/status_effects/xeno_buffs.dm b/code/datums/status_effects/xeno_buffs.dm
index 630fd1dfde48d..3490750cb1dbc 100644
--- a/code/datums/status_effects/xeno_buffs.dm
+++ b/code/datums/status_effects/xeno_buffs.dm
@@ -870,3 +870,485 @@
 	xeno_owner.xeno_melee_damage_modifier -= modifier
 	xeno_owner.remove_filter("frenzy_screech_outline")
 	return ..()
+
+// ***************************************
+// *********** Upgrade Chambers Buffs
+// ***************************************
+/datum/status_effect/mutation_upgrade
+	/// Owner typed as an xenomorph.
+	var/mob/living/carbon/xenomorph/buff_owner
+	/// The structure to base chamber_scaling on.
+	var/chamber_structure
+	/// The amount of times to multiply the main effect by.
+	var/chamber_scaling = 0
+
+/datum/status_effect/mutation_upgrade/on_apply()
+	if(!isxeno(owner))
+		return FALSE
+	buff_owner = owner
+	update_chamber_scaling()
+	return TRUE
+
+/// Sets the chamber_scaling based on the amount of chambers in the xeno's hive.
+/datum/status_effect/mutation_upgrade/proc/update_chamber_scaling()
+	switch(chamber_structure)
+		if(MUTATION_STRUCTURE_CHAMBER)
+			chamber_scaling = length(buff_owner.hive?.shell_chambers)
+		if(MUTATION_STRUCTURE_SPUR)
+			chamber_scaling = length(buff_owner.hive?.spur_chambers)
+		if(MUTATION_STRUCTURE_VEIL)
+			chamber_scaling = length(buff_owner.hive?.veil_chambers)
+
+// ***************************************
+// *********** Upgrade Chambers Buffs - Survival
+// ***************************************
+/atom/movable/screen/alert/status_effect/carapace
+	name = "Carapace"
+	desc = "Armor increased."
+	icon_state = "xenobuff_carapace"
+
+/datum/status_effect/mutation_upgrade/carapace
+	id = "mutation_upgrade_carapace"
+	alert_type = /atom/movable/screen/alert/status_effect/carapace
+	chamber_structure = MUTATION_STRUCTURE_CHAMBER
+	/// The amount of hard armor given.
+	var/armor_buff_per_chamber = 1
+
+/datum/status_effect/mutation_upgrade/carapace/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL, PROC_REF(update_buff))
+	buff_owner.hard_armor = buff_owner.hard_armor.modifyAllRatings(armor_buff_per_chamber * chamber_scaling)
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/carapace/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL)
+	buff_owner.hard_armor = buff_owner.hard_armor.modifyAllRatings(-armor_buff_per_chamber * chamber_scaling)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active survival chambers and adjusts soft armor accordingly.
+/datum/status_effect/mutation_upgrade/carapace/proc/update_buff()
+	SIGNAL_HANDLER
+	buff_owner.hard_armor = buff_owner.hard_armor.modifyAllRatings(armor_buff_per_chamber * (length(buff_owner.hive.shell_chambers) - chamber_scaling))
+	update_chamber_scaling()
+
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/regeneration
+	name = "Regeneration"
+	desc = "Regeneration increased."
+	icon_state = "xenobuff_regeneration"
+
+/datum/status_effect/mutation_upgrade/regeneration
+	id = "mutation_upgrade_regeneration"
+	alert_type = /atom/movable/screen/alert/status_effect/regeneration
+	chamber_structure = MUTATION_STRUCTURE_CHAMBER
+	/// The amount of max health to be regenerated everytime the proc 'heal_wounds' is called.
+	var/health_regen_per_chamber = 0.008 // 0.8%
+	/// The amount of sunder to be regenerated everytime the proc 'heal_wounds' is called.
+	var/sunder_regen_per_chamber = 0.166
+
+/datum/status_effect/mutation_upgrade/regeneration/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL, PROC_REF(update_buff))
+	RegisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN, PROC_REF(on_heal_wounds))
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/regeneration/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL)
+	UnregisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active survival chambers.
+/datum/status_effect/mutation_upgrade/regeneration/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+
+/// Heals the xenomorph's health and sunder based on assigned variables.
+/datum/status_effect/mutation_upgrade/regeneration/proc/on_heal_wounds(mob/living/carbon/xenomorph/source_xenomorph, heal_data, seconds_per_tick)
+	SIGNAL_HANDLER
+	if(!chamber_scaling)
+		return
+	var/health_amount = buff_owner.maxHealth * health_regen_per_chamber * chamber_scaling
+	var/sunder_amount = -sunder_regen_per_chamber * chamber_scaling
+	HEAL_XENO_DAMAGE(buff_owner, health_amount, FALSE)
+	buff_owner.adjust_sunder(sunder_amount)
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/vampirism
+	name = "Vampirism"
+	desc = "Leech from attacks."
+	icon_state = "xenobuff_vampirism"
+
+/datum/status_effect/mutation_upgrade/vampirism
+	id = "mutation_upgrade_vampirism"
+	alert_type = /atom/movable/screen/alert/status_effect/vampirism
+	chamber_structure = MUTATION_STRUCTURE_CHAMBER
+	/// The percentage of damage dealt to be healed after hitting an alive human.
+	var/leech_buff_per_chamber = 0.1
+
+/datum/status_effect/mutation_upgrade/vampirism/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL, PROC_REF(update_buff))
+	RegisterSignal(buff_owner, COMSIG_XENOMORPH_POSTATTACK_LIVING, PROC_REF(on_postattack))
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/vampirism/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_SURVIVAL)
+	UnregisterSignal(buff_owner, COMSIG_XENOMORPH_POSTATTACK_LIVING)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active survival chambers.
+/datum/status_effect/mutation_upgrade/vampirism/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+
+/// Heals the xenomorph for hitting a non-dead human by a percentage of their max health.
+/datum/status_effect/mutation_upgrade/vampirism/proc/on_postattack(datum/source, mob/living/target, damage_done)
+	SIGNAL_HANDLER
+	if(target.stat == DEAD || !ishuman(target))
+		return
+	var/health_amount = damage_done * leech_buff_per_chamber * chamber_scaling
+	HEAL_XENO_DAMAGE(buff_owner, health_amount, FALSE)
+
+// ***************************************
+// *********** Upgrade Chambers Buffs - Attack
+// ***************************************
+/atom/movable/screen/alert/status_effect/celerity
+	name = "Celerity"
+	desc = "Run faster."
+	icon_state = "xenobuff_attack"
+
+/datum/status_effect/mutation_upgrade/celerity
+	id = "mutation_upgrade_celerity"
+	alert_type = /atom/movable/screen/alert/status_effect/celerity
+	chamber_structure = MUTATION_STRUCTURE_SPUR
+	/// The amount of movement speed the owner get.
+	var/speed_buff_per_chamber = 0.05
+
+/datum/status_effect/mutation_upgrade/celerity/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK, PROC_REF(update_buff))
+	buff_owner.add_movespeed_modifier(MOVESPEED_ID_CELERITY_BUFF, TRUE, 0, NONE, TRUE, -speed_buff_per_chamber * chamber_scaling)
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/celerity/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK)
+	buff_owner.remove_movespeed_modifier(MOVESPEED_ID_CELERITY_BUFF)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active spur chambers and adjusts movement speed accordingly.
+/datum/status_effect/mutation_upgrade/celerity/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+	buff_owner.add_movespeed_modifier(MOVESPEED_ID_CELERITY_BUFF, TRUE, 0, NONE, TRUE, -speed_buff_per_chamber * chamber_scaling)
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/adrenaline
+	name = "Adrenaline"
+	desc = "Regenerate plasma."
+	icon_state = "xenobuff_attack"
+
+/datum/status_effect/mutation_upgrade/adrenaline
+	id = "mutation_upgrade_adrenaline"
+	alert_type = /atom/movable/screen/alert/status_effect/adrenaline
+	chamber_structure = MUTATION_STRUCTURE_SPUR
+	/// The amount of plasma to regenerate based on their caste's plasma regeneration.
+	var/plasma_regen_buff_per_chamber = 0.1 // 10%
+	/// The amount of plasma to regenerate based on their caste's maximum plasma.
+	var/plasma_maximum_buff_per_chamber = 0.01 // 1%
+
+/datum/status_effect/mutation_upgrade/adrenaline/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK, PROC_REF(update_buff))
+	RegisterSignal(buff_owner, COMSIG_XENOMORPH_PLASMA_REGEN, PROC_REF(on_plasma_regen))
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/adrenaline/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK)
+	UnregisterSignal(buff_owner, COMSIG_XENOMORPH_PLASMA_REGEN)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active spur chambers.
+/datum/status_effect/mutation_upgrade/adrenaline/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+
+/// Gives the xenomorph more plasma (according to their plasma regeneration and adjusted maximum) everytime they are suppose to regen plasma up to their adjusted maximum.
+/datum/status_effect/mutation_upgrade/adrenaline/proc/on_plasma_regen(mob/living/carbon/xenomorph/source_xenomorph, plasma_mod, seconds_per_tick)
+	SIGNAL_HANDLER
+	if(!chamber_scaling)
+		return
+
+	var/adjusted_plasma_maximum = buff_owner.xeno_caste.plasma_max * buff_owner.xeno_caste.plasma_regen_limit
+	var/plasma_from_regeneration = buff_owner.xeno_caste.plasma_gain * plasma_regen_buff_per_chamber * chamber_scaling
+	var/plasma_from_maximum = adjusted_plasma_maximum * plasma_maximum_buff_per_chamber * chamber_scaling
+	var/plasma_to_give = (plasma_from_regeneration + plasma_from_maximum) * ((buff_owner.resting || buff_owner.lying_angle) ? 2 : 1)
+	plasma_to_give = clamp(plasma_to_give, 0, adjusted_plasma_maximum - buff_owner.plasma_stored)
+	buff_owner.gain_plasma(plasma_to_give)
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/crush
+	name = "Crush"
+	desc = "Additional damage to objects."
+	icon_state = "xenobuff_attack"
+
+/datum/status_effect/mutation_upgrade/crush
+	id = "mutation_upgrade_crush"
+	alert_type = /atom/movable/screen/alert/status_effect/crush
+	chamber_structure = MUTATION_STRUCTURE_SPUR
+	/// The bonus damage to deal as percentage.
+	var/damage_buff_per_chamber = 0.333 // 33.3%
+	/// The armour pentration the damage damage has.
+	var/penetration_buff_per_chamber = 10
+
+/datum/status_effect/mutation_upgrade/crush/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK, PROC_REF(update_buff))
+	RegisterSignal(buff_owner, COMSIG_XENOMORPH_ATTACK_OBJ, PROC_REF(on_obj_attack))
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/crush/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_ATTACK)
+	UnregisterSignal(buff_owner, COMSIG_XENOMORPH_ATTACK_OBJ)
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active spur chambers.
+/datum/status_effect/mutation_upgrade/crush/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+
+/// Deals bonus damage along with armour pentration to the object.
+/datum/status_effect/mutation_upgrade/crush/proc/on_obj_attack(datum/source, obj/attacked)
+	SIGNAL_HANDLER
+	if(!chamber_scaling)
+		return
+	if(attacked.resistance_flags & XENO_DAMAGEABLE)
+		var/adjusted_armour_penetration = penetration_buff_per_chamber * chamber_scaling
+		var/adjusted_damage = buff_owner.xeno_caste.melee_damage * damage_buff_per_chamber * chamber_scaling
+		var/expected_damage = round(attacked.modify_by_armor(adjusted_damage, MELEE, adjusted_armour_penetration, null, null), DAMAGE_PRECISION)
+		var/expected_integrity = max(attacked.obj_integrity - expected_damage, 0)
+		// Since this signal is called before they actually attack themselves, we do just enough so the main attack does the finishing blow.
+		if(!expected_integrity)
+			attacked.take_damage(expected_integrity - 0.1, BRUTE, MELEE, FALSE, armour_penetration = 100)
+			return
+		attacked.take_damage(buff_owner.xeno_caste.melee_damage * damage_buff_per_chamber * chamber_scaling, BRUTE, MELEE, FALSE, armour_penetration = (penetration_buff_per_chamber * chamber_scaling))
+
+// ***************************************
+// *********** Upgrade Chambers Buffs - Utility
+// ***************************************
+/atom/movable/screen/alert/status_effect/focus
+	name = "Focus"
+	desc = "Increases attack damage."
+	icon_state = "xenobuff_generic"
+
+/datum/status_effect/mutation_upgrade/focus
+	id = "mutation_upgrade_focus"
+	alert_type = /atom/movable/screen/alert/status_effect/focus
+	chamber_structure = MUTATION_STRUCTURE_VEIL
+	/// The bonus melee damage for each chamber.
+	var/damage_buff_per_chamber = 1
+
+/datum/status_effect/mutation_upgrade/focus/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY, PROC_REF(update_buff))
+	buff_owner.xeno_caste.melee_damage += damage_buff_per_chamber * chamber_scaling
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/focus/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY)
+	buff_owner.xeno_caste.melee_damage -= damage_buff_per_chamber * chamber_scaling
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active veil chambers.
+/datum/status_effect/mutation_upgrade/focus/proc/update_buff()
+	SIGNAL_HANDLER
+	buff_owner.xeno_caste.melee_damage -= damage_buff_per_chamber * chamber_scaling
+	update_chamber_scaling()
+	buff_owner.xeno_caste.melee_damage += damage_buff_per_chamber * chamber_scaling
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/camouflage
+	name = "Camouflage"
+	desc = "Increases your capabilities of stealth."
+	icon_state = "xenobuff_generic"
+
+/datum/status_effect/mutation_upgrade/camouflage
+	id = "mutation_upgrade_camouflage"
+	alert_type = /atom/movable/screen/alert/status_effect/camouflage
+	chamber_structure = MUTATION_STRUCTURE_VEIL
+	var/actively_cloaked = FALSE
+
+/datum/status_effect/mutation_upgrade/camouflage/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY, PROC_REF(update_buff))
+	ADD_TRAIT(buff_owner, TRAIT_SILENT_FOOTSTEPS, XENO_BUFF_TRAIT)
+	if(chamber_scaling >= 2)
+		ADD_TRAIT(buff_owner, TRAIT_TACTICAL_SENSOR_IMMUNE, XENO_BUFF_TRAIT)
+	if(chamber_scaling >= 3)
+		RegisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN, PROC_REF(give_camouflage))
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/camouflage/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY)
+	REMOVE_TRAIT(buff_owner, TRAIT_SILENT_FOOTSTEPS, XENO_BUFF_TRAIT)
+	if(chamber_scaling >= 2)
+		REMOVE_TRAIT(buff_owner, TRAIT_TACTICAL_SENSOR_IMMUNE, XENO_BUFF_TRAIT)
+	if(chamber_scaling >= 3)
+		remove_camouflage()
+		UnregisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN, PROC_REF(give_camouflage))
+	return ..()
+
+/// Sets the chamber_scaling to the amount of active veil chambers.
+/datum/status_effect/mutation_upgrade/camouflage/proc/update_buff()
+	SIGNAL_HANDLER
+	var/previous_chamber_scale = chamber_scaling
+	update_chamber_scaling()
+	// No change at all.
+	if(previous_chamber_scale == chamber_scaling)
+		return
+	// Scaling down.
+	if(previous_chamber_scale > chamber_scaling)
+		// Removes things based on the difference.
+		for(var/i = (chamber_scaling + 1) to previous_chamber_scale)
+			switch(i)
+				if(1)
+					REMOVE_TRAIT(buff_owner, TRAIT_SILENT_FOOTSTEPS, XENO_BUFF_TRAIT)
+				if(2)
+					REMOVE_TRAIT(buff_owner, TRAIT_TACTICAL_SENSOR_IMMUNE, XENO_BUFF_TRAIT)
+				if(3)
+					remove_camouflage()
+					UnregisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN)
+		return
+	// Scaling up.
+	for(var/i = (previous_chamber_scale + 1) to chamber_scaling)
+		switch(i)
+			if(1)
+				ADD_TRAIT(buff_owner, TRAIT_SILENT_FOOTSTEPS, XENO_BUFF_TRAIT)
+			if(2)
+				ADD_TRAIT(buff_owner, TRAIT_TACTICAL_SENSOR_IMMUNE, XENO_BUFF_TRAIT)
+			if(3)
+				give_camouflage()
+				RegisterSignal(buff_owner, COMSIG_XENOMORPH_HEALTH_REGEN, PROC_REF(give_camouflage))
+
+/// Sets the alpha of the owner to normal.
+/datum/status_effect/mutation_upgrade/camouflage/proc/remove_camouflage()
+	buff_owner.alpha = initial(buff_owner.alpha)
+	UnregisterSignal(buff_owner, COMSIG_XENOMORPH_TAKING_DAMAGE)
+
+/// Sets the alpha of the owner if their alpha is normal.
+/datum/status_effect/mutation_upgrade/camouflage/proc/give_camouflage()
+	// No giving camouflage if they already got it or getting their alpha set by something else.
+	if(buff_owner.alpha != 255)
+		return
+	buff_owner.alpha = 64
+	RegisterSignal(buff_owner, COMSIG_XENOMORPH_TAKING_DAMAGE, PROC_REF(remove_camouflage))
+
+// ***************************************
+// ***************************************
+// ***************************************
+/atom/movable/screen/alert/status_effect/pheromones
+	name = "Pheromones"
+	desc = "Allows to emit pheromones. Click to change pheromones."
+	icon_state = "xenobuff_phero"
+
+/atom/movable/screen/alert/status_effect/pheromones/Click()
+	var/datum/status_effect/mutation_upgrade/pheromones/status_effect = attached_effect
+	var/phero_choice = show_radial_menu(status_effect.buff_owner, status_effect.buff_owner, GLOB.pheromone_images_list, radius = 35, require_near = TRUE)
+	if(!phero_choice)
+		return
+	QDEL_NULL(status_effect.current_aura)
+	status_effect.emitted_aura = phero_choice
+	status_effect.create_aura()
+
+/datum/status_effect/mutation_upgrade/pheromones
+	id = "mutation_upgrade_pheromones"
+	alert_type = /atom/movable/screen/alert/status_effect/pheromones
+	chamber_structure = MUTATION_STRUCTURE_VEIL
+	/// The aura if it is not using the xeno's aura from pheromones ability.
+	var/datum/aura_bearer/current_aura
+	/// The aura to emit.
+	var/emitted_aura = AURA_XENO_RECOVERY
+	/// The initial value of the aura's power.
+	var/aura_power_base = 1
+	/// The phero power to increase by.
+	var/aura_power_per_chamber = 0.25
+
+/datum/status_effect/mutation_upgrade/pheromones/on_apply()
+	if(!..())
+		return FALSE
+	RegisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY, PROC_REF(update_buff))
+	create_aura()
+	return TRUE
+
+/datum/status_effect/mutation_upgrade/pheromones/on_remove()
+	UnregisterSignal(SSdcs, COMSIG_UPGRADE_CHAMBER_UTILITY)
+	if(current_aura)
+		current_aura.stop_emitting()
+	switch(emitted_aura)
+		if(AURA_XENO_RECOVERY)
+			var/datum/action/ability/xeno_action/pheromones/emit_recovery/recovery_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_recovery]
+			if(recovery_pheromones)
+				recovery_pheromones.bonus_aura_strength = initial(recovery_pheromones.bonus_aura_strength)
+				recovery_pheromones.apply_pheros(AURA_XENO_RECOVERY)
+		if(AURA_XENO_WARDING)
+			var/datum/action/ability/xeno_action/pheromones/emit_warding/warding_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_warding]
+			if(warding_pheromones)
+				warding_pheromones.bonus_aura_strength = initial(warding_pheromones.bonus_aura_strength)
+				warding_pheromones.apply_pheros(AURA_XENO_WARDING)
+		if(AURA_XENO_FRENZY)
+			var/datum/action/ability/xeno_action/pheromones/emit_frenzy/frenzy_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_frenzy]
+			if(frenzy_pheromones)
+				frenzy_pheromones.bonus_aura_strength = initial(frenzy_pheromones.bonus_aura_strength)
+				frenzy_pheromones.apply_pheros(AURA_XENO_FRENZY)
+	return ..()
+
+/// Boosts the current aura (if they have pheromones already) or creates a aura.
+/datum/status_effect/mutation_upgrade/pheromones/proc/create_aura()
+	if(current_aura)
+		current_aura.stop_emitting()
+	switch(emitted_aura)
+		if(AURA_XENO_RECOVERY)
+			var/datum/action/ability/xeno_action/pheromones/emit_recovery/recovery_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_recovery]
+			if(recovery_pheromones)
+				recovery_pheromones.bonus_aura_strength = aura_power_per_chamber * chamber_scaling
+				recovery_pheromones.apply_pheros(AURA_XENO_RECOVERY)
+				return
+		if(AURA_XENO_WARDING)
+			var/datum/action/ability/xeno_action/pheromones/emit_warding/warding_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_warding]
+			if(warding_pheromones)
+				warding_pheromones.bonus_aura_strength = aura_power_per_chamber * chamber_scaling
+				warding_pheromones.apply_pheros(AURA_XENO_WARDING)
+				return
+		if(AURA_XENO_FRENZY)
+			var/datum/action/ability/xeno_action/pheromones/emit_frenzy/frenzy_pheromones = buff_owner.actions_by_path[/datum/action/ability/xeno_action/pheromones/emit_frenzy]
+			if(frenzy_pheromones)
+				frenzy_pheromones.bonus_aura_strength = aura_power_per_chamber * chamber_scaling
+				frenzy_pheromones.apply_pheros(AURA_XENO_FRENZY)
+				return
+	if(!chamber_scaling)
+		return
+	current_aura = SSaura.add_emitter(buff_owner, emitted_aura, 6 + aura_power_per_chamber * chamber_scaling * 2, aura_power_base + aura_power_per_chamber * chamber_scaling, -1, FACTION_XENO, buff_owner.hivenumber)
+
+/// Sets the chamber_scaling to the amount of active veil chambers and recreates the aura.
+/datum/status_effect/mutation_upgrade/pheromones/proc/update_buff()
+	SIGNAL_HANDLER
+	update_chamber_scaling()
+	create_aura()
diff --git a/code/game/objects/items/cocoon.dm b/code/game/objects/items/cocoon.dm
index 1073e7361a96c..9265b61242297 100644
--- a/code/game/objects/items/cocoon.dm
+++ b/code/game/objects/items/cocoon.dm
@@ -44,8 +44,10 @@
 	psych_points_output = clamp(psych_points_output, COCOON_PSY_POINTS_REWARD_MIN, COCOON_PSY_POINTS_REWARD_MAX)
 	SSpoints.add_strategic_psy_points(hivenumber, psych_points_output)
 	SSpoints.add_tactical_psy_points(hivenumber, psych_points_output*0.25)
-	//Gives marine cloneloss for a total of 30.
+	// Gives marine cloneloss for a total of 30.
 	victim.adjustCloneLoss(0.5)
+	// Slowly give biomass over time up to 18 biomass (assuming the time based on comment above is correct).
+	SSpoints.add_biomass_points(hivenumber, 0.3)
 
 /obj/structure/cocoon/take_damage(damage_amount, damage_type = BRUTE, armor_type = null, effects = TRUE, attack_dir, armour_penetration = 0, mob/living/blame_mob)
 	. = ..()
@@ -71,6 +73,8 @@
 		var/datum/hive_status/hive_status = GLOB.hive_datums[hivenumber]
 		hive_status.update_tier_limits()
 		GLOB.round_statistics.larva_from_cocoon += larva_point_reward / xeno_job.job_points_needed
+		SSpoints.add_biomass_points(hivenumber, 12)
+
 		release_victim()
 	update_icon()
 
diff --git a/code/game/objects/items/motion_detector.dm b/code/game/objects/items/motion_detector.dm
index 1f0bce3d96a6a..2cc15c41c6473 100644
--- a/code/game/objects/items/motion_detector.dm
+++ b/code/game/objects/items/motion_detector.dm
@@ -136,7 +136,9 @@
 			continue
 		prepare_blip(nearby_human, nearby_human.wear_id?.iff_signal & operator.wear_id.iff_signal ? MOTION_DETECTOR_FRIENDLY : MOTION_DETECTOR_HOSTILE)
 	for (var/mob/living/carbon/xenomorph/nearby_xeno AS in cheap_get_xenos_near(operator, range))
-		if(nearby_xeno.last_move_time + move_sensitivity < world.time )
+		if(nearby_xeno.last_move_time + move_sensitivity < world.time)
+			continue
+		if(HAS_TRAIT(nearby_xeno, TRAIT_TACTICAL_SENSOR_IMMUNE))
 			continue
 		prepare_blip(nearby_xeno, MOTION_DETECTOR_HOSTILE)
 	if(hostile_detected)
diff --git a/code/game/objects/structures/xeno.dm b/code/game/objects/structures/xeno.dm
index 1d6f768981852..7a582b6a70fda 100644
--- a/code/game/objects/structures/xeno.dm
+++ b/code/game/objects/structures/xeno.dm
@@ -145,6 +145,10 @@
 	ignore_weed_destruction = FALSE
 	refundable = FALSE
 
+/obj/alien/resin/sticky/thin/temporary/Initialize(mapload)
+	. = ..()
+	addtimer(CALLBACK(src, PROC_REF(obj_destruction), MELEE), 3 SECONDS)
+
 //Resin Doors
 /obj/structure/mineral_door/resin
 	name = RESIN_DOOR
diff --git a/code/modules/mob/dead/observer/observer.dm b/code/modules/mob/dead/observer/observer.dm
index 10c85e8c91ba9..57b555009f7ba 100644
--- a/code/modules/mob/dead/observer/observer.dm
+++ b/code/modules/mob/dead/observer/observer.dm
@@ -907,6 +907,7 @@ GLOBAL_VAR_INIT(observer_default_invisibility, INVISIBILITY_OBSERVER)
 		new_xeno.apply_assigned_role_to_spawn(xallhala_job)
 		SSpoints.xeno_strategic_points_by_hive[XENO_HIVE_FALLEN] = 10000
 		SSpoints.xeno_tactical_points_by_hive[XENO_HIVE_FALLEN] = 10000
+		SSpoints.xeno_biomass_points_by_hive[XENO_HIVE_FALLEN] = 500
 		mind.transfer_to(new_xeno, TRUE)
 		xallhala_job.after_spawn(new_xeno)
 		return
diff --git a/code/modules/mob/living/carbon/xenomorph/abilities.dm b/code/modules/mob/living/carbon/xenomorph/abilities.dm
index 51c774ef65351..22a82282e6661 100644
--- a/code/modules/mob/living/carbon/xenomorph/abilities.dm
+++ b/code/modules/mob/living/carbon/xenomorph/abilities.dm
@@ -633,6 +633,8 @@
 	ability_cost = 30
 	desc = "Opens your pheromone options."
 	use_state_flags = ABILITY_USE_STAGGERED|ABILITY_USE_NOTTURF|ABILITY_USE_BUSY|ABILITY_USE_LYING
+	/// Additional aura strength which will be added to the caste's aura strength.
+	var/bonus_aura_strength = 0
 
 /datum/action/ability/xeno_action/pheromones/proc/apply_pheros(phero_choice)
 	var/mob/living/carbon/xenomorph/X = owner
@@ -645,7 +647,8 @@
 		X.hud_set_pheromone()
 		return fail_activate()
 	QDEL_NULL(X.current_aura)
-	X.current_aura = SSaura.add_emitter(X, phero_choice, 6 + X.xeno_caste.aura_strength * 2, X.xeno_caste.aura_strength, -1, X.faction, X.hivenumber)
+	var/aura_strength = X.xeno_caste.aura_strength + bonus_aura_strength
+	X.current_aura = SSaura.add_emitter(X, phero_choice, 6 + aura_strength * 2, aura_strength, -1, X.faction, X.hivenumber)
 	X.balloon_alert(X, "[phero_choice]")
 	playsound(X.loc, SFX_ALIEN_DROOL, 25)
 
@@ -1398,6 +1401,7 @@
 
 	victim.do_jitter_animation(2)
 	victim.adjustCloneLoss(20)
+	SSpoints.add_biomass_points(X.hivenumber, 15)
 
 	ADD_TRAIT(victim, TRAIT_PSY_DRAINED, TRAIT_PSY_DRAINED)
 	if(HAS_TRAIT(victim, TRAIT_UNDEFIBBABLE))
@@ -1509,6 +1513,7 @@
 	victim.dead_ticks = 0
 	ADD_TRAIT(victim, TRAIT_STASIS, TRAIT_STASIS)
 	X.eject_victim(TRUE, starting_turf)
+
 	if(owner.client)
 		var/datum/personal_statistics/personal_statistics = GLOB.personal_statistics_list[owner.ckey]
 		personal_statistics.cocooned++
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/baneling/castedatum_baneling.dm b/code/modules/mob/living/carbon/xenomorph/castes/baneling/castedatum_baneling.dm
index 705d0a4fc4850..f3356533ed536 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/baneling/castedatum_baneling.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/baneling/castedatum_baneling.dm
@@ -24,7 +24,7 @@
 	max_health = 100
 
 	// *** Flags *** //
-	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION
+	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED
 	caste_traits = null
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/beetle/castedatum_beetle.dm b/code/modules/mob/living/carbon/xenomorph/castes/beetle/castedatum_beetle.dm
index 94dc092dc0630..21c46d7720a3a 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/beetle/castedatum_beetle.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/beetle/castedatum_beetle.dm
@@ -24,7 +24,7 @@
 	max_health = 260
 
 	// *** Flags *** //
-	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION
+	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_RIDE_CRUSHER
 	caste_traits = null
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/hivemind/castedatum_hivemind.dm b/code/modules/mob/living/carbon/xenomorph/castes/hivemind/castedatum_hivemind.dm
index 32fff1412c34f..a0512db0764b4 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/hivemind/castedatum_hivemind.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/hivemind/castedatum_hivemind.dm
@@ -22,7 +22,7 @@
 
 	maximum_active_caste = 1
 	// *** Flags *** //
-	caste_flags = CASTE_INNATE_PLASMA_REGEN|CASTE_FIRE_IMMUNE|CASTE_IS_BUILDER|CASTE_DO_NOT_ALERT_LOW_LIFE
+	caste_flags = CASTE_INNATE_PLASMA_REGEN|CASTE_FIRE_IMMUNE|CASTE_IS_BUILDER|CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_BE_GIVEN_PLASMA
 	caste_traits = null
 
@@ -74,7 +74,7 @@
 	upgrade = XENO_UPGRADE_MANIFESTATION
 
 	// *** Flags *** //
-	caste_flags = CASTE_IS_BUILDER|CASTE_FIRE_IMMUNE
+	caste_flags = CASTE_IS_BUILDER|CASTE_FIRE_IMMUNE|CASTE_NO_MUTATION
 
 	aura_strength = 4 //Good pheros
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/mantis/castedatum_mantis.dm b/code/modules/mob/living/carbon/xenomorph/castes/mantis/castedatum_mantis.dm
index 190fa40955b4b..9b71d0df965fd 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/mantis/castedatum_mantis.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/mantis/castedatum_mantis.dm
@@ -25,7 +25,7 @@
 	max_health = 150
 
 	// *** Flags *** //
-	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION
+	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_BE_GIVEN_PLASMA|CASTE_CAN_RIDE_CRUSHER
 	caste_traits = null
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/nymph/castedatum_nymph.dm b/code/modules/mob/living/carbon/xenomorph/castes/nymph/castedatum_nymph.dm
index ad381f39c107f..f897a8ccfffc6 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/nymph/castedatum_nymph.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/nymph/castedatum_nymph.dm
@@ -24,7 +24,7 @@
 	max_health = 120
 
 	// *** Flags *** //
-	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_IS_BUILDER
+	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_IS_BUILDER|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_BE_GIVEN_PLASMA
 
 	// *** Defense *** //
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/puppet/castedatum_puppet.dm b/code/modules/mob/living/carbon/xenomorph/castes/puppet/castedatum_puppet.dm
index 6840b7fb279cd..82f8fa4d00b5e 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/puppet/castedatum_puppet.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/puppet/castedatum_puppet.dm
@@ -15,7 +15,7 @@
 	plasma_max = 2
 	plasma_gain = 0
 	max_health = 250
-	caste_flags = CASTE_NOT_IN_BIOSCAN|CASTE_DO_NOT_ANNOUNCE_DEATH|CASTE_DO_NOT_ALERT_LOW_LIFE
+	caste_flags = CASTE_NOT_IN_BIOSCAN|CASTE_DO_NOT_ANNOUNCE_DEATH|CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_NO_MUTATION
 	minimap_icon = "puppet"
 	soft_armor = list(MELEE = 14, BULLET = 3, LASER = 5, ENERGY = 3, BOMB = 0, BIO = 0, FIRE = 0, ACID = 0)
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/scorpion/castedatum_scorpion.dm b/code/modules/mob/living/carbon/xenomorph/castes/scorpion/castedatum_scorpion.dm
index 42102310c5e56..6dc30aa83fcfd 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/scorpion/castedatum_scorpion.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/scorpion/castedatum_scorpion.dm
@@ -24,7 +24,7 @@
 	max_health = 130
 
 	// *** Flags *** //
-	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION
+	caste_flags = CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_A_MINION|CASTE_NO_MUTATION
 	can_flags = CASTE_CAN_BE_QUEEN_HEALED|CASTE_CAN_BE_GIVEN_PLASMA|CASTE_CAN_RIDE_CRUSHER
 	caste_traits = null
 
diff --git a/code/modules/mob/living/carbon/xenomorph/castes/spiderling/castedatum_spiderling.dm b/code/modules/mob/living/carbon/xenomorph/castes/spiderling/castedatum_spiderling.dm
index 45a9b323f78d3..e9c7964f079ff 100644
--- a/code/modules/mob/living/carbon/xenomorph/castes/spiderling/castedatum_spiderling.dm
+++ b/code/modules/mob/living/carbon/xenomorph/castes/spiderling/castedatum_spiderling.dm
@@ -25,7 +25,7 @@
 	max_health = 125
 
 	// *** Flags *** //
-	caste_flags = CASTE_NOT_IN_BIOSCAN|CASTE_DO_NOT_ANNOUNCE_DEATH|CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_BUILDER
+	caste_flags = CASTE_NOT_IN_BIOSCAN|CASTE_DO_NOT_ANNOUNCE_DEATH|CASTE_DO_NOT_ALERT_LOW_LIFE|CASTE_IS_BUILDER|CASTE_NO_MUTATION
 
 	// *** Minimap Icon *** //
 	minimap_icon = "spiderling"
diff --git a/code/modules/mob/living/carbon/xenomorph/hive_datum.dm b/code/modules/mob/living/carbon/xenomorph/hive_datum.dm
index 2accf2293d193..36f621f1e5735 100644
--- a/code/modules/mob/living/carbon/xenomorph/hive_datum.dm
+++ b/code/modules/mob/living/carbon/xenomorph/hive_datum.dm
@@ -24,6 +24,13 @@
 	var/list/obj/structure/xeno/pherotower/pherotowers = list()
 	///list of hivemind cores
 	var/list/obj/structure/xeno/hivemindcore/hivemindcores = list()
+	/// List of shell upgrade chambers.
+	var/list/obj/structure/xeno/upgrade_chamber/shell/shell_chambers = list()
+	/// List of spur upgrade chambers.
+	var/list/obj/structure/xeno/upgrade_chamber/spur/spur_chambers = list()
+	/// List of veil upgrade chambers.
+	var/list/obj/structure/xeno/upgrade_chamber/veil/veil_chambers = list()
+
 	var/tier3_xeno_limit
 	var/tier2_xeno_limit
 	/// Queue of all clients wanting to join xeno side
@@ -35,6 +42,9 @@
 	var/datum/hive_purchases/purchases = new
 	/// The nuke HUD timer datum, shown on each xeno's screen
 	var/atom/movable/screen/text/screen_timer/nuke_hud_timer
+	/// The amount of biomass stored.
+	var/biomass = 0
+
 
 // ***************************************
 // *********** Init
@@ -122,6 +132,13 @@
 	// Pheromone towers
 	for(var/obj/structure/xeno/pherotower/tower AS in GLOB.hive_datums[hivenumber].pherotowers)
 		.["hive_structures"] += list(get_structure_packet(tower))
+	// Upgrade chambers
+	for(var/obj/structure/xeno/upgrade_chamber/shell/chamber AS in GLOB.hive_datums[hivenumber].shell_chambers)
+		.["hive_structures"] += list(get_structure_packet(chamber))
+	for(var/obj/structure/xeno/upgrade_chamber/spur/chamber AS in GLOB.hive_datums[hivenumber].spur_chambers)
+		.["hive_structures"] += list(get_structure_packet(chamber))
+	for(var/obj/structure/xeno/upgrade_chamber/veil/chamber AS in GLOB.hive_datums[hivenumber].veil_chambers)
+		.["hive_structures"] += list(get_structure_packet(chamber))
 	// Hivemind cores
 	for(var/obj/structure/xeno/hivemindcore/core AS in GLOB.hive_datums[hivenumber].hivemindcores)
 		.["hive_structures"] += list(get_structure_packet(core))
@@ -145,6 +162,7 @@
 			"is_leader" = xeno.xeno_flags & XENO_LEADER,
 			"is_ssd" = !xeno.client,
 			"index" = GLOB.hive_ui_caste_index[caste.caste_type_path],
+			"mutation_disabled" = caste.caste_flags & CASTE_NO_MUTATION
 		))
 
 	var/mob/living/carbon/xenomorph/xeno_user
@@ -163,7 +181,7 @@
 	.["user_maturity"] = isxeno(user) ? xeno_user.upgrade_stored : 0
 	.["user_next_mat_level"] = isxeno(user) && xeno_user.upgrade_possible() ? xeno_user.xeno_caste.upgrade_threshold : 0
 	.["user_tracked"] = isxeno(user) && !isnull(xeno_user.tracked) ? REF(xeno_user.tracked) : ""
-
+	.["user_can_mutate"] = !isxeno(user) || (xeno_user.xeno_caste.caste_flags & CASTE_NO_MUTATION)
 	.["user_show_empty"] = !!(user.client.prefs.status_toggle_flags & HIVE_STATUS_SHOW_EMPTY)
 	.["user_show_compact"] = !!(user.client.prefs.status_toggle_flags & HIVE_STATUS_COMPACT_MODE)
 	.["user_show_general"] = !!(user.client.prefs.status_toggle_flags & HIVE_STATUS_SHOW_GENERAL)
@@ -262,6 +280,10 @@
 			if(!isxeno(usr))
 				return
 			SEND_SIGNAL(usr, COMSIG_XENOABILITY_BLESSINGSMENU)
+		if("Mutations")
+			if(!isxeno(usr))
+				return
+			GLOB.mutation_selector.interact(usr)
 		if("Compass")
 			var/atom/target = locate(params["target"])
 			if(isobserver(usr))
@@ -1589,3 +1611,4 @@ to_chat will check for valid clients itself already so no need to double check f
 	if(faction == FACTION_ZOMBIE)
 		return FACTION_ZOMBIE
 	return FALSE
+
diff --git a/code/modules/mob/living/carbon/xenomorph/hive_upgrades.dm b/code/modules/mob/living/carbon/xenomorph/hive_upgrades.dm
index 6bca6e42502ce..9a51507d5f4e4 100644
--- a/code/modules/mob/living/carbon/xenomorph/hive_upgrades.dm
+++ b/code/modules/mob/living/carbon/xenomorph/hive_upgrades.dm
@@ -314,6 +314,50 @@ GLOBAL_LIST_INIT(tier_to_primo_upgrade, list(
 			to_chat(buyer, span_xenowarning("You cannot build in a dense location!"))
 		return FALSE
 
+/datum/hive_upgrade/building/upgrade_chamber
+	gamemode_flags = ABILITY_NUCLEARWAR
+	building_loc = 0
+	/// The maximum amount of buildings that can exist before being disallowed from buying more.
+	var/max_chambers = 3
+
+/datum/hive_upgrade/building/upgrade_chamber/shell
+	name = "Shell Upgrade Chamber"
+	desc = "Constructs a chamber that allows xenos to buy survival mutations. Build up to 3 structures to increase mutation power."
+	icon = "shell"
+	psypoint_cost = 250
+	building_type = /obj/structure/xeno/upgrade_chamber/shell
+
+/datum/hive_upgrade/building/upgrade_chamber/shell/can_buy(mob/living/carbon/xenomorph/buyer, silent = TRUE)
+	. = ..()
+	if(length(buyer.hive.shell_chambers) >= max_chambers)
+		to_chat(buyer, span_xenowarning("Hive cannot support more than [max_chambers] active shell chambers!"))
+		return FALSE
+
+/datum/hive_upgrade/building/upgrade_chamber/spur
+	name = "Spur Upgrade Chamber"
+	desc = "Constructs a chamber that allows xenos to buy attack mutations. Build up to 3 structures to increase mutation power."
+	icon = "spur"
+	psypoint_cost = 200
+	building_type = /obj/structure/xeno/upgrade_chamber/spur
+
+/datum/hive_upgrade/building/upgrade_chamber/spur/can_buy(mob/living/carbon/xenomorph/buyer, silent = TRUE)
+	. = ..()
+	if(length(buyer.hive.spur_chambers) >= max_chambers)
+		to_chat(buyer, span_xenowarning("Hive cannot support more than [max_chambers] active spur chambers!"))
+		return FALSE
+
+/datum/hive_upgrade/building/upgrade_chamber/veil
+	name = "Veil Upgrade Chamber"
+	desc = "Constructs a chamber that allows xenos to buy utility mutations. Build up to 3 structures to increase mutation power."
+	icon = "veil"
+	psypoint_cost = 300
+	building_type = /obj/structure/xeno/upgrade_chamber/veil
+
+/datum/hive_upgrade/building/upgrade_chamber/veil/can_buy(mob/living/carbon/xenomorph/buyer, silent = TRUE)
+	. = ..()
+	if(length(buyer.hive.veil_chambers) >= max_chambers)
+		to_chat(buyer, span_xenowarning("Hive cannot support more than [max_chambers] active veil chambers!"))
+		return FALSE
 
 /datum/hive_upgrade/defence
 	category = "Defences"
diff --git a/code/modules/mob/living/carbon/xenomorph/mutation_datum.dm b/code/modules/mob/living/carbon/xenomorph/mutation_datum.dm
new file mode 100644
index 0000000000000..c517e9c4ea12e
--- /dev/null
+++ b/code/modules/mob/living/carbon/xenomorph/mutation_datum.dm
@@ -0,0 +1,208 @@
+/datum/mutation_datum
+	interaction_flags = INTERACT_UI_INTERACT
+
+/datum/mutation_datum/ui_state(mob/user)
+	return GLOB.hive_ui_state // Similar purpose.
+
+/datum/mutation_datum/ui_interact(mob/user, datum/tgui/ui)
+	ui = SStgui.try_update_ui(user, src, ui)
+	if(!ui)
+		ui = new(user, src, "MutationSelector", "Mutation Selector")
+		ui.open()
+
+/datum/mutation_datum/ui_data(mob/living/carbon/xenomorph/xeno_user)
+	var/list/data = list()
+
+	data["shell_chambers"] = length(xeno_user.hive?.shell_chambers)
+	data["spur_chambers"] = length(xeno_user.hive?.spur_chambers)
+	data["veil_chambers"] = length(xeno_user.hive?.veil_chambers)
+	data["biomass"] = !isnull(SSpoints.xeno_biomass_points_by_hive[xeno_user.hivenumber]) ? SSpoints.xeno_biomass_points_by_hive[xeno_user.hivenumber] : 0
+	return data
+
+/datum/mutation_datum/ui_static_data(mob/living/carbon/xenomorph/xeno_user)
+	var/list/data = list()
+
+	// Cost is not expected to change as switching castes closes the UI.
+	switch(xeno_user.xeno_caste.tier)
+		if(XENO_TIER_ONE)
+			data["cost"] = XENO_UPGRADE_BIOMASS_COST_T1
+		if(XENO_TIER_TWO)
+			data["cost"] = XENO_UPGRADE_BIOMASS_COST_T2
+		if(XENO_TIER_THREE)
+			data["cost"] = XENO_UPGRADE_BIOMASS_COST_T3
+		else
+			data["cost"] = XENO_UPGRADE_BIOMASS_COST_T4
+
+	data["survival_mutations"] = list()
+	for(var/datum/mutation_upgrade/survival/subtype_survival_mutation AS in subtypesof(/datum/mutation_upgrade/survival))
+		data["survival_mutations"] += list(list( // Double listing is how it needs to work.
+			"name" = subtype_survival_mutation.name,
+			"desc" = subtype_survival_mutation.desc,
+			"owned" = locate(subtype_survival_mutation.status_effect) in xeno_user.status_effects
+		))
+
+	data["attack_mutations"] = list()
+	for(var/datum/mutation_upgrade/attack/subtype_attack_mutation AS in subtypesof(/datum/mutation_upgrade/attack))
+		data["attack_mutations"] += list(list(
+			"name" = subtype_attack_mutation.name,
+			"desc" = subtype_attack_mutation.desc,
+			"owned" = locate(subtype_attack_mutation.status_effect) in xeno_user.status_effects
+		))
+
+	data["utility_mutations"] = list()
+	for(var/datum/mutation_upgrade/utility/subtype_utility_mutation AS in subtypesof(/datum/mutation_upgrade/utility))
+		data["utility_mutations"] += list(list(
+			"name" = subtype_utility_mutation.name,
+			"desc" = subtype_utility_mutation.desc,
+			"owned" = locate(subtype_utility_mutation.status_effect) in xeno_user.status_effects
+		))
+
+	return data
+
+/datum/mutation_datum/ui_act(action, params)
+	. = ..()
+	if(.)
+		return
+	if(!isxeno(usr))
+		return
+
+	switch(action)
+		if("purchase")
+			try_purchase_mutation(usr, params["upgrade_name"])
+
+	SStgui.close_user_uis(usr, src)
+
+/// Tries to purchase a mutation. Denies if possible. Otherwise, removes conflicting mutations and gives the purchased mutation.
+/datum/mutation_datum/proc/try_purchase_mutation(mob/living/carbon/xenomorph/xeno_purchaser, upgrade_name)
+	if(!xeno_purchaser.hive || !upgrade_name)
+		return
+	if((xeno_purchaser.xeno_caste.caste_flags & CASTE_NO_MUTATION))
+		return
+
+	var/upgrade_price
+	switch(xeno_purchaser.xeno_caste.tier)
+		if(XENO_TIER_ONE)
+			upgrade_price = XENO_UPGRADE_BIOMASS_COST_T1
+		if(XENO_TIER_TWO)
+			upgrade_price = XENO_UPGRADE_BIOMASS_COST_T2
+		if(XENO_TIER_THREE)
+			upgrade_price = XENO_UPGRADE_BIOMASS_COST_T3
+		else
+			upgrade_price = XENO_UPGRADE_BIOMASS_COST_T4
+
+	var/current_biomass = !isnull(SSpoints.xeno_biomass_points_by_hive[xeno_purchaser.hivenumber]) ? SSpoints.xeno_biomass_points_by_hive[xeno_purchaser.hivenumber] : 0
+	if(current_biomass < upgrade_price)
+		to_chat(usr, span_warning("The hive does not have enough biomass!"))
+		return
+
+	var/datum/mutation_upgrade/chosen_mutation_upgrade
+	for(var/datum/mutation_upgrade/subtype_mutation AS in GLOB.mutation_upgrades_buyable)
+		if(subtype_mutation.name == upgrade_name)
+			chosen_mutation_upgrade = subtype_mutation
+			break
+
+	if(!chosen_mutation_upgrade)
+		return
+
+	switch(chosen_mutation_upgrade.required_structure)
+		if(MUTATION_STRUCTURE_CHAMBER)
+			if(!length(xeno_purchaser.hive.shell_chambers))
+				to_chat(usr, span_xenonotice("This mutation requires a shell chamber to exist!"))
+				return
+		if(MUTATION_STRUCTURE_SPUR)
+			if(!length(xeno_purchaser.hive.spur_chambers))
+				to_chat(usr, span_xenonotice("This mutation requires a spur chamber to exist!"))
+				return
+		if(MUTATION_STRUCTURE_VEIL)
+			if(!length(xeno_purchaser.hive.veil_chambers))
+				to_chat(usr, span_xenonotice("This mutation requires a veil chamber to exist!"))
+				return
+
+	var/existing_upgrade = locate(chosen_mutation_upgrade.status_effect) in xeno_purchaser.status_effects
+	if(existing_upgrade)
+		to_chat(usr, span_xenonotice("Existing mutation chosen. No biomass spent."))
+		return
+
+	var/list/mutation_status_effects_to_remove = list()
+	for(var/datum/mutation_upgrade/subtype_mutation AS in GLOB.mutation_upgrades_buyable)
+		if(chosen_mutation_upgrade.category == subtype_mutation.category)
+			mutation_status_effects_to_remove += subtype_mutation.status_effect
+
+	SSpoints.xeno_biomass_points_by_hive[xeno_purchaser.hivenumber] -= upgrade_price
+	to_chat(xeno_purchaser, span_xenonotice("Mutation gained."))
+	for(var/datum/status_effect/removed_status_effect AS in mutation_status_effects_to_remove)
+		xeno_purchaser.remove_status_effect(removed_status_effect)
+	xeno_purchaser.do_jitter_animation(500)
+	xeno_purchaser.apply_status_effect(chosen_mutation_upgrade.status_effect)
+	xeno_message("[xeno_purchaser] has purchased [chosen_mutation_upgrade.name] Mutation.", "xenoannounce", 5, xeno_purchaser.hivenumber)
+
+/datum/mutation_upgrade
+	/// The name that is displayed in the TGUI.
+	var/name
+	/// The description that is displayed in the TGUI.
+	var/desc
+	/// The category slot that this upgrade takes. Upgrades that conflict with this category slot will be removed/replaced.
+	var/category
+	/// The structure that needs to exist for a successful purchase.
+	var/required_structure
+	/// The status effect given upon successful purchase.
+	var/datum/status_effect/status_effect
+
+/datum/mutation_upgrade/survival
+	category = MUTATION_CATEGORY_SURVIVAL
+	required_structure = MUTATION_STRUCTURE_CHAMBER
+
+/datum/mutation_upgrade/survival/carapace
+	name = "Carapace"
+	desc = "Increases our hard armor by 1 per Shell Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_CARAPACE
+
+/datum/mutation_upgrade/survival/regeneration
+	name = "Regeneration"
+	desc = "When regenerating health on weeds, regenerate 0.8% max health and 0.167 sunder per Shell Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_REGENERATION
+
+/datum/mutation_upgrade/survival/vampirism
+	name = "Vampirism"
+	desc = "When slashing living humans, heal 10% for damage dealt per Shell Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_VAMPIRISM
+
+/datum/mutation_upgrade/attack
+	category = MUTATION_CATEGORY_ATTACK
+	required_structure = MUTATION_STRUCTURE_SPUR
+
+/datum/mutation_upgrade/attack/celerity
+	name = "Celerity"
+	desc = "Move -0.1 units faster per Spur Chamber."
+	category = MUTATION_CATEGORY_ATTACK
+	required_structure = MUTATION_STRUCTURE_SPUR
+	status_effect = STATUS_EFFECT_UPGRADE_CELERITY
+
+/datum/mutation_upgrade/attack/adrenaline
+	name = "Adrenaline"
+	desc = "When regenerating plasma on weeds, regenerate 5% additional plasma and 1% maximum plasma per Spur Chamber. It is doubled if resting."
+	status_effect = STATUS_EFFECT_UPGRADE_ADRENALINE
+
+/datum/mutation_upgrade/attack/crush
+	name = "Crush"
+	desc = "When attacking structures, deal a second instance of damage that is a 1/3 of your melee damage with 15 AP per Spur Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_CRUSH
+
+/datum/mutation_upgrade/utility
+	category = MUTATION_CATEGORY_UTILITY
+	required_structure = MUTATION_STRUCTURE_VEIL
+
+/datum/mutation_upgrade/utility/focus
+	name = "Focus"
+	desc = "Deal 1 additional melee damage for every Veil Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_FOCUS
+
+/datum/mutation_upgrade/utility/pheromones
+	name = "Pheromones"
+	desc = "Allows you to emit a chosen pheromone starting at a power of 1 and an additional 0.25 per Veil Chamber."
+	status_effect = STATUS_EFFECT_UPGRADE_PHERO
+
+/datum/mutation_upgrade/utility/camouflage
+	name = "Camouflage"
+	desc = "Grants various stealth effects based on the amount of Veil Chambers: slient step (1), immunity to tactical sensor detection (2), and stealth that is broken when taking damage & regained when healing (3)."
+	status_effect = STATUS_EFFECT_UPGRADE_CAMOUFLAGE
diff --git a/code/modules/mob/living/carbon/xenomorph/xenoprocs.dm b/code/modules/mob/living/carbon/xenomorph/xenoprocs.dm
index a173fb124683d..737f1bfe8d58a 100644
--- a/code/modules/mob/living/carbon/xenomorph/xenoprocs.dm
+++ b/code/modules/mob/living/carbon/xenomorph/xenoprocs.dm
@@ -126,6 +126,9 @@
 	else //Upgrade process finished or impossible
 		. += "Upgrade Progress: (FINISHED)"
 
+	if(!(xeno_caste.caste_flags & CASTE_NO_MUTATION))
+		. += "Biomass: [!isnull(SSpoints.xeno_biomass_points_by_hive[hivenumber]) ? SSpoints.xeno_biomass_points_by_hive[hivenumber] : 0]/500"
+
 	. += "Health: [health]/[maxHealth][overheal ? " + [overheal]": ""]" //Changes with balance scalar, can't just use the caste
 
 	if(xeno_caste.plasma_max > 0)
diff --git a/code/modules/xenomorph/upgrade_chambers.dm b/code/modules/xenomorph/upgrade_chambers.dm
new file mode 100644
index 0000000000000..719d05adb0a09
--- /dev/null
+++ b/code/modules/xenomorph/upgrade_chambers.dm
@@ -0,0 +1,62 @@
+/obj/structure/xeno/upgrade_chamber
+	name = "upgrade chamber"
+	desc = "You shouldn't see this!"
+	icon = 'icons/Xeno/1x1building.dmi'
+	icon_state = "shell_chamber"
+	bound_width = 32
+	bound_height = 32
+	max_integrity = 500
+	resistance_flags = UNACIDABLE | DROPSHIP_IMMUNE
+	xeno_structure_flags = IGNORE_WEED_REMOVAL | CRITICAL_STRUCTURE
+
+/obj/structure/xeno/upgrade_chamber/Initialize(mapload, _hivenumber)
+	. = ..()
+	SSminimaps.add_marker(src, MINIMAP_FLAG_XENO, image('icons/UI_icons/map_blips.dmi', null, "upgrade_chamber", ABOVE_FLOAT_LAYER))
+
+/obj/structure/xeno/upgrade_chamber/shell
+	name = "Shell Chamber"
+	desc = "Shell upgrade chamber"
+	icon_state = "shell_chamber"
+
+/obj/structure/xeno/upgrade_chamber/shell/Initialize(mapload, _hivenumber)
+	. = ..()
+	set_light(3, 1, COLOR_DARK_CYAN)
+	GLOB.hive_datums[hivenumber].shell_chambers += src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_SURVIVAL)
+
+/obj/structure/xeno/upgrade_chamber/shell/Destroy()
+	GLOB.hive_datums[hivenumber].shell_chambers -= src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_SURVIVAL)
+	return ..()
+
+/obj/structure/xeno/upgrade_chamber/spur
+	name = "Spur Chamber"
+	desc = "Spur upgrade chamber"
+	icon_state = "spur_chamber"
+
+/obj/structure/xeno/upgrade_chamber/spur/Initialize(mapload, _hivenumber)
+	. = ..()
+	set_light(3, 1, COLOR_RED)
+	GLOB.hive_datums[hivenumber].spur_chambers += src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_ATTACK)
+
+/obj/structure/xeno/upgrade_chamber/spur/Destroy()
+	GLOB.hive_datums[hivenumber].spur_chambers -= src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_ATTACK)
+	return ..()
+
+/obj/structure/xeno/upgrade_chamber/veil
+	name = "Veil Chamber"
+	desc = "Veil upgrade chamber"
+	icon_state = "veil_chamber"
+
+/obj/structure/xeno/upgrade_chamber/veil/Initialize(mapload, _hivenumber)
+	. = ..()
+	set_light(3, 1, COLOR_LIME)
+	GLOB.hive_datums[hivenumber].veil_chambers += src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_UTILITY)
+
+/obj/structure/xeno/upgrade_chamber/veil/Destroy()
+	GLOB.hive_datums[hivenumber].veil_chambers -= src
+	SEND_GLOBAL_SIGNAL(COMSIG_UPGRADE_CHAMBER_UTILITY)
+	return ..()
diff --git a/icons/UI_Icons/buyable_icons.dmi b/icons/UI_Icons/buyable_icons.dmi
index 0401dbb393f75..985131ed198f3 100644
Binary files a/icons/UI_Icons/buyable_icons.dmi and b/icons/UI_Icons/buyable_icons.dmi differ
diff --git a/icons/UI_Icons/map_blips.dmi b/icons/UI_Icons/map_blips.dmi
index b38bbe215fb77..fa6c1cd80f6e3 100644
Binary files a/icons/UI_Icons/map_blips.dmi and b/icons/UI_Icons/map_blips.dmi differ
diff --git a/icons/Xeno/1x1building.dmi b/icons/Xeno/1x1building.dmi
index b58708b539aa3..d4ac402de1aaf 100644
Binary files a/icons/Xeno/1x1building.dmi and b/icons/Xeno/1x1building.dmi differ
diff --git a/icons/mob/screen_alert.dmi b/icons/mob/screen_alert.dmi
index ad6e246e92201..af132dd3a6ac6 100644
Binary files a/icons/mob/screen_alert.dmi and b/icons/mob/screen_alert.dmi differ
diff --git a/tgmc.dme b/tgmc.dme
index d016dc2755e2d..ab21b3a09e63b 100644
--- a/tgmc.dme
+++ b/tgmc.dme
@@ -1789,6 +1789,7 @@ F// DM Environment file for baystation12.dme.
 #include "code\modules\mob\living\carbon\xenomorph\hive_upgrades.dm"
 #include "code\modules\mob\living\carbon\xenomorph\life.dm"
 #include "code\modules\mob\living\carbon\xenomorph\login.dm"
+#include "code\modules\mob\living\carbon\xenomorph\mutation_datum.dm"
 #include "code\modules\mob\living\carbon\xenomorph\saddles.dm"
 #include "code\modules\mob\living\carbon\xenomorph\say.dm"
 #include "code\modules\mob\living\carbon\xenomorph\update_icons.dm"
@@ -2284,6 +2285,7 @@ F// DM Environment file for baystation12.dme.
 #include "code\modules\xenomorph\spawner.dm"
 #include "code\modules\xenomorph\trap.dm"
 #include "code\modules\xenomorph\tunnel.dm"
+#include "code\modules\xenomorph\upgrade_chambers.dm"
 #include "code\modules\xenomorph\xeno_turret.dm"
 #include "code\modules\xenomorph\xenoplant.dm"
 #include "code\modules\xenomorph\xenotowers.dm"
diff --git a/tgui/packages/tgui/interfaces/HiveStatus.tsx b/tgui/packages/tgui/interfaces/HiveStatus.tsx
index 5f89779d85c8e..f7cae197cb00f 100644
--- a/tgui/packages/tgui/interfaces/HiveStatus.tsx
+++ b/tgui/packages/tgui/interfaces/HiveStatus.tsx
@@ -44,6 +44,7 @@ type InputPack = {
   user_evolution: number;
   user_purchase_perms: boolean;
   user_maturity: number;
+  user_can_mutate: boolean;
   user_next_mat_level: number;
   user_tracked: string;
   user_show_compact: boolean;
@@ -190,15 +191,12 @@ const BlessingsButton = (_props: any) => {
   const { act, data } = useBackend<InputPack>();
   const { user_purchase_perms, user_ref } = data;
 
-  if (!user_purchase_perms) {
-    return <Box />;
-  }
-
   return (
     <Box className="Section__buttons">
       <Button
         onClick={() => act('Blessings', { xeno: user_ref })}
         icon={'store'}
+        disabled={!user_purchase_perms}
       >
         Blessings
       </Button>
@@ -206,6 +204,23 @@ const BlessingsButton = (_props: any) => {
   );
 };
 
+const MutationsButton = (_props: any) => {
+  const { act, data } = useBackend<InputPack>();
+  const { user_ref, user_can_mutate } = data;
+
+  return (
+    <Box className="Section__buttons" mr="90px">
+      <Button
+        onClick={() => act('Mutations', { xeno: user_ref })}
+        icon={'store'}
+        disabled={!!user_can_mutate}
+      >
+        Mutations
+      </Button>
+    </Box>
+  );
+};
+
 const GeneralInfo = (_props: any) => {
   const { data } = useBackend<InputPack>();
   const {
@@ -253,7 +268,10 @@ const GeneralInfo = (_props: any) => {
             {' ' + hive_larva_burrowed}
           </Box>
         </Box>
-        <BlessingsButton />
+        <Box as="span">
+          <MutationsButton />
+          <BlessingsButton />
+        </Box>
       </Box>
       <Flex direction="column" className="Section__content">
         <Flex.Item>
diff --git a/tgui/packages/tgui/interfaces/MutationSelector.tsx b/tgui/packages/tgui/interfaces/MutationSelector.tsx
new file mode 100644
index 0000000000000..03321ae94ba37
--- /dev/null
+++ b/tgui/packages/tgui/interfaces/MutationSelector.tsx
@@ -0,0 +1,168 @@
+import { useBackend } from '../backend';
+import {
+  Button,
+  Collapsible,
+  Flex,
+  ProgressBar,
+  Section,
+  Tooltip,
+} from '../components';
+import { Window } from '../layouts';
+
+type Upgrade = {
+  name: string;
+  desc: string;
+  owned: boolean;
+};
+
+type BiomassData = {
+  biomass: number;
+  cost: number;
+};
+
+type SurvivalMutationData = {
+  survival_mutations: Upgrade[];
+  shell_chambers: number;
+  biomass: number;
+  cost: number;
+};
+
+type AttackMutationData = {
+  attack_mutations: Upgrade[];
+  spur_chambers: number;
+  biomass: number;
+  cost: number;
+};
+
+type UtilityMutationData = {
+  utility_mutations: Upgrade[];
+  veil_chambers: number;
+  biomass: number;
+  cost: number;
+};
+
+export const MutationSelector = (_props: any) => {
+  return (
+    <Window theme="xeno" width={500} height={600}>
+      <Window.Content scrollable>
+        <Section title="Biomass" key="Biomass">
+          <BiomassBar />
+        </Section>
+        <SurvivalMutationSection />
+        <AttackMutationSection />
+        <UtilityMutationSection />
+      </Window.Content>
+    </Window>
+  );
+};
+
+const BiomassBar = (_props: any) => {
+  const { data } = useBackend<BiomassData>();
+  const { biomass, cost } = data;
+
+  return (
+    <Tooltip content={`Costs ${cost} biomass to buy an upgrade!`}>
+      <Flex mb={1}>
+        <Flex.Item grow>
+          <ProgressBar color="green" value={biomass / 500}>
+            {`${biomass} / 500 `}
+          </ProgressBar>
+        </Flex.Item>
+      </Flex>
+    </Tooltip>
+  );
+};
+
+const SurvivalMutationSection = (_props: any) => {
+  const { act, data } = useBackend<SurvivalMutationData>();
+  const { survival_mutations, shell_chambers, cost, biomass } = data;
+
+  return (
+    <Collapsible
+      title={`Survival Mutations | Shell Chambers: ${shell_chambers}/3`}
+    >
+      {survival_mutations.map((mutation) => (
+        <Section
+          title={`${mutation.name}`}
+          mb={1}
+          key={mutation.name}
+          buttons={
+            <Button
+              content={`Buy (${cost})`}
+              key={mutation.name}
+              onClick={() => act('purchase', { upgrade_name: mutation.name })}
+              disabled={cost > biomass || shell_chambers === 0}
+              selected={mutation.owned}
+            />
+          }
+        >
+          <Flex direction="column-reverse" align={'left'}>
+            {mutation.desc}
+          </Flex>
+        </Section>
+      ))}
+    </Collapsible>
+  );
+};
+
+const AttackMutationSection = (_props: any) => {
+  const { act, data } = useBackend<AttackMutationData>();
+  const { attack_mutations, spur_chambers, cost, biomass } = data;
+
+  return (
+    <Collapsible title={`Attack Mutations | Spur Chambers: ${spur_chambers}/3`}>
+      {attack_mutations.map((mutation) => (
+        <Section
+          title={`${mutation.name}`}
+          mb={1}
+          key={mutation.name}
+          buttons={
+            <Button
+              content={`Buy (${cost})`}
+              key={mutation.name}
+              onClick={() => act('purchase', { upgrade_name: mutation.name })}
+              disabled={cost > biomass || spur_chambers === 0}
+              selected={mutation.owned}
+            />
+          }
+        >
+          <Flex direction="column-reverse" align={'left'}>
+            {mutation.desc}
+          </Flex>
+        </Section>
+      ))}
+    </Collapsible>
+  );
+};
+
+const UtilityMutationSection = (_props: any) => {
+  const { act, data } = useBackend<UtilityMutationData>();
+  const { utility_mutations, veil_chambers, cost, biomass } = data;
+
+  return (
+    <Collapsible
+      title={`Utility Mutations | Veil Chambers: ${veil_chambers}/3`}
+    >
+      {utility_mutations.map((mutation) => (
+        <Section
+          title={`${mutation.name}`}
+          mb={1}
+          key={mutation.name}
+          buttons={
+            <Button
+              content={`Buy (${cost})`}
+              key={mutation.name}
+              onClick={() => act('purchase', { upgrade_name: mutation.name })}
+              disabled={cost > biomass || veil_chambers === 0}
+              selected={mutation.owned}
+            />
+          }
+        >
+          <Flex direction="column-reverse" align={'left'}>
+            {mutation.desc}
+          </Flex>
+        </Section>
+      ))}
+    </Collapsible>
+  );
+};