Jet Jaguar

An advanced robot created by Japanese inventor Goro Ibuki, Jet Jaguar was stolen by the Seatopians and used to guide their guardian monster Megalon in his destruction of the surface world. Goro managed to sever the Seatopians' control of the robot, only to discover that Jet Jaguar had become self-aware and altered his own programming. Jet Jaguar used his newfound power to recruit the assistance of Godzilla, then grew to gigantic size to battle Megalon and Gigan. With Godzilla's aid, Jet Jaguar drove off the villainous monsters and saved the Earth, then returned to his creator.