South Park Episode 607 - "Simpsons Already Did It"

Professor Chaos (okay, it's just Butters) returns with brand new, super evil, schemes to wreak havoc on South Park; unfortunately, the Simpsons have already done them all.

Meanwhile, a super secret ingredient helps Cartman's "Sea People" evolve at an alarming rate. Stan, Kyle, and new friend Tweek, costar. Kenny is still dead.