Two young boys sneak aboard a spaceship and find themselves whisked away to the mysterious planet Terra. There, they encounter Gamera's old foe Gyaos and two female aliens with a taste for human brains. Gamera must save the children and battle the new monster Guiron, whose entire body is a deadly living weapon.

• Daiei Film
• Nobuhiro Kajima
• Christopher Murphy
• Miyuki Akiyama
• Eiji Funakoshi
• Kon Omura
• Yūko Hamada
• Edith Hansen
• Reiko Kasahara