S5·E17 Zach and the Alien Invaders
Aired November 9, 1991
Synopsis
Zach, the Turtles' young friend, and honorary fifth Turtle, is infatuated with comic books, especially 'The Alien Invaders.' Zach retires his Turtle costume when his parents enroll him in the Ten-Hut Military Academy where they hope he will learn some discipline and live in the real world.