Monster from a Prehistoric Planet was released in the year 1967。Monster from a Prehistoric Planet is also called as Daikyojû Gappa, the Triphibian Monster, o Monstro Gigante, la bestia gigante, Gappa, Gappa the Triphibian Monsters, Gappa il mostro che minaccia il mondo, Gappa - Frankensteins fliegende Monster。

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.