Monsters From a Prehistoric Planet

A Japanese tycoon sends out an expedition to a remote South Pacific island to investigate the story of some mysterious creatures revered as gods. Arriving with reporters in tow, the expedition soon discovers a small reptilian creature in an underground cavern. Despite the warnings of the natives to leave it alone, the expedition takes the creature, known as Gappa, back to Japan to be exhibited at the tycoon's theme park. Unfortunately, the creature's parents decide to retrieve their baby and storm Japan intent on doing so, regardless of the damage they must inflict.