Gappa, The Triphibian Monster (1967)

aka's: Daikyojû Gappa/Monster From The Prehistoric Planet/ The Giant Beast Gappa/
大巨獣ガッパ

Widescreen Version

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 then warn the foreigners to leave the hatchling alone, but they ignore the warnings and take it back to a zoo in Japan. Soon after, chaos develops as Gappa's parents start demolishing Tokyo, looking for their kidnapped child. Features a fine display of special effects.

This is the only giant monster film (kaijû eiga) released by Nikkatsu studios. Unfortunately, after this film was released, the company nearly went out of business.