That is amazing, just read through everything!
If possible, try to put down a rather complicated example of an existing (or made) creature to show how it's been done, just for examples sake.
Also: "A hair is attached to an entity, and an entity can only have one hair."
Doesn't the Creators second form have more than one... "hair"? (tentacle)
Or do the tentacles have animations? Or are they separate entities?
Anyway, small things like that should also be cool to explain.