Liam McCracken

Liam McCracken is the main antagonist of the Phineas and Ferb episode Primal Perry.

Biography
Liam's hatred of platypus started at a young age. In Australia, his mother was distracted by a platypus, leaving Liam and his stroller to roll away.

After Perry the platypus is sent to Danville Botanical Gardens, Doofenshmirtz reveals to have hired Liam to trap him. This quickly gets out of hand when Liam threatens to make a trophy out of Perry, and Doof as well.

The two foes work together to defeat Liam, avoiding his boomerangs. He proves to be one of the few villains who stand a fair fight against Perry. He is only ultimately stopped by Doofenshmirtz and some groundskeepers.