Varan the Unbelievable

During an excursion to research an unusual butterfly in the mountains of northeastern Japan, two explorers are mysteriously killed. The natives of the island blame the deaths on their God "Varan" who becomes enraged at the sight of humans. A second group of researchers, not heeding the natives' warning, rouse the gigantic angry beast and evoke the destruction of the native village. The Self-Defense force launches a counterattack; battleships, tanks, and high-powered explosives, deployed to halt the spiney-backed, flying creature as it heads for the ultimate stomping ground -- TOKYO. (official distributor synopsis)