An expedition in the South Pacific lands on a tropical island where the natives worship the mysterious deity Gappa. An earthquake opens up an underground cavern and a baby reptile is discovered inside. The natives warn the foreigners to leave the hatching alone, but they don't listen and take it back to a zoo in Japan. Soon after, moma and papa Gappa start smashing Tokyo looking for their kidnapped child.

• Nikkatsu Corporation
• Manson International
• Tamio Kawachi
• Yōko Yamamoto
• Yuji Okada
• Kōji Wada
• Tatsuya Fuji
• Keisuke Inoue
• Zenji Yamada
• Bumon Kahara