Play E.V.O. long enough and you'll find this hidden grove of dinosaurs that talk about these weird creatures with the head of a cat and the body of a rabbit.

If you decide to take that fairly obvious clue, you end up with your cat-rabbit thing

From there, choose 'Body' → 'Ramothecus Body' to spend 5000 of your EVO points and become a monkey.

From there, keep going back to 'Body' → 'Evolve Further', and you'll evolve further (duh)

And again

For Human Form!

The human is kind of quick, and has a decent attack with that club. But this is definitely a one-way path. Once you hit this, there's no turning back and no more experimenting with combinations of body parts.

You also might be wondering how the same creature can evolve both into a female mermaid and a male caveman. And to that I'd just like to remind you to repeat to yourself that it's just a game and you should really just relax.