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.
Alternative titles: Gappa, the Triphibian Monster | The Giant Beast Gappa | Gappa: ¡El monstruo del horror! | Gappa, o Monstro Gigante | Gappa | Gappa, le descendant de Godzilla | Gappa – Invasion der fliegenden Bestien | Gappa, to teras tis thalassas | Gappa il mostro che minaccia il mondo | 大巨獣ガッパ | Gappa, los monstruos del Pacífico | The Triphibian Monster | Гигантский монстр Гаппа | El monstruo que amenaza al mundo | Gappa the Triphibian Monster | Gappa the Triphibian Monsters | Monster from a Prehistoric Planet | Gappa – Frankensteins fliegende Monster