I had an OP Pteranodon once upon a time. She's SilkWing, the Assassin. She got no mutations, just by leveling up, I eventually got her into 10k health, 3k stam, 400+ weight, and a freakin' 1.4k melee. With her, I perfected my Hit-and-Run tactic and she can handle most of the things we're fighting, even a mf Giga. I deleted the world she's in unfortunately...