Mechaturtle

Mechaturtle is a villain from the 1987 video game Teenage Mutant Ninja Turtles. He is the boss of the third level.

Appearance
Mechaturtle's initial appearance is that of a blue-green, purple, or blue skinned Teenage Mutant Ninja Turtle with a tan or green headband and joint pads. Upon this form's defeat, it reveals its true appearance; a vaguely turtlesque automaton.

Confusion
Many fans mistake him as Slash who is another villain in the TMNT franchise. Both of these characters are entirely separate. Slash has spoken at least once whereas Mechaturtle is entirely silent. Also, Slash never transformed into a robot unlike Mechaturtle.