Japan Special Effects Film Co., Ltd.

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.

The spaceship AAB-Gamma is dispatched from FAFC headquarters in Japan to make a landing on the planet Mars and investigate reports of UFOs in the area. As they near the red planet, they encounter a mysterious UFO that coats the ship's hull with unusual spores. Taking one of the specimens back to earth, it soon develops and grows into a giant chicken-lizard-alien monster that tramples Japan.

Kenichi Horie is determined to challenge his family, the law and the nature crossing the Pacific to America in a small sailboat. Despite his careful planning, many unforeseen events will test his determination.