They should drop the rng element. None of the apes are good pets, even as far as pets go (which isn’t very far). There is no reason to make them so hard to get, especially the Black Yeti that requires you to completely assemble the Scourgestone every time you want to roll for a 1/5 chance.
(Also, they should add Baboon pets and make them come from a Molten Heart…)