I feel like I've seen a challenge like this before or titled the rogue male challenge..
Start with 1 male creature with derp snout, deformed paws, and other than that randomize it.
As soon as you find a female wanderer, invite them. Mate with them, and when they have a male babey kick 'em out.
Kick out any female babey.
Continue the cycle with the babey being the new rogue, and if the father didn't die yet kick 'em out.