Makes it worth it to run around a squad or two of these guys with your other armies so you can fill out some of the other races units that you like. The Heritor do not evolve so much as when their ghost guys hit max level they get a new ability that lets them take over another unit permently, almost any other unit that isnt mindless. Usually not worth the energy to make them until you get the big melee guy that pumps them out whenever he eats somebody, and then only for fun. The Kirko ones are 'ok' but they only turn into 2 rank II and become slightly more useful critters, random mind you.

Wish amazons could take the whales and turtles in the ocean, would make building a defensive navy a lot easier. Not sure about some of the others, hope somebody else can point them out. Beatle Babies die too much to keep them alive usually but they turn into the big poppas and die almost as much. The hopperhounds are pretty nice at rank III and can be end game useful with a few mods. Theres a couple like the kitty that I do not think level up at all, at least past rank II. Its kind of a pain keeping them alive through every fight but some of them turn out alright.

Not all of them do that though and none of them do it past rank III critters. Once it levels up enough and hits prime rank (max level) it kicks to the next evolution, kinda like how the kirko grubs do the same thing and I think a few other critters.

The amazons age of wonders: planetfall