Gojira tai Megaro 1973
Directed by Jun Fukuda | Starring: Katsuhiko Sasaki, Hiroyuki Kawase, Yutaka Hayashi, Robert Dunham
Inventor Goro Ibuki creates a humanoid robot named Jet Jaguar. It is soon seized by an undersea race of people called the Seatopians. Using Jet Jaguar as a guide, the Seatopians send Megalon as vengeance for the nuclear tests that have devastated their society.