Season 6
| Episode 22 -
Head Of State
An old enemy from the past returns, and he wants Bishop destroyed and only the Turtles can help him. However, when Bishop is kidnapped, the Turtles learn that before he became the Global President and cleaned up his act, he did some "dirty work" for the Earth Protection Force-- poaching and gene splicing aliens. It turns out that in 2055, there was a lab accident that had catastrophic results...