Steve Martin
Shinkichi (as Tuyoaki Suzuki)
Security Officer Tomo Iwanaga (as Frank Iwaiga)
Ogata (as Akiro Takarata)
Dr. Serizawa
Hagiwara
Dr. Yamane
Emiko Yamane (as Momaku Kuchi)
Dr. Tabata (uncredited)
Seiji (uncredited)
George Lawrence (uncredited)
President of Company (uncredited)
Dr. Tabata's Assistant (uncredited)
The Old Fisherman (uncredited)
Man on Boat (uncredited)
Godzilla (uncredited)
Godzilla (uncredited)
Unidentified Character (voice)
Unidentified Character (voice)
Unidentified Character (voice)
Unidentified Character (voice)
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Unidentified Character (voice)