Suggestion: Adding custom mod variants via datapack/config?

[Afrocntrik]

Either through config files or a datapack, allowing for a subspace of "modname:entity", "texture/paths" and "weights.json"
I would love to add custom variants of Mutant Monsters in the Minecraft Earth Style or just adding the removed Green Axolotl and others.
Either way thank you so much you have made a great mod!