Teenage Mutant Ninja Turtles (1987): Season 5, Episode 3

5 - 3: My Brother, the Bad Guy

A family secret is revealed when Lieutenant Kazou Saki arrives from Japan to arrest his brother Oroku Saki, who turns out to be the Turtles' greatest enemy. Shredder and Krang send the Technodrome from Dimension X to Earth, but Donatello re-programs it to crash in the Arctic.