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.
as Hiroshi Kurosaki
as Itoko Koyanagi
as Daize Tonooka
as Mashida
as George Inoue
as President Funazu
as Captain of the Kamome-maru
as Elder
as Reporter #1
as Hosoda
as Cmdr. Riku
as The Professor
as Saburo Hayashi
as Oyama
as Aihara
as Islander 1
as Reporter 2
as Islander 2
as Reporter 3
as Islander 3
as Reporter 4
as Petty Officer
as Captain of the Sea Angels
as Professor