Varan the Unbelievable

Varan the Unbelievable, released in Japan as Giant Monster Varan , Daikaij Baran? , is a 1958 Japanese science fiction kaiju film directed by Ishir Honda. The film focuses on Varan, a prehistoric creature reawakened by scientific experiments performed on the lake where Varan resides. The film stars Kz Nomura, Ayumi Sonoda, Fumito Matsuo, and Haruo Nakajima as Varan. The film is produced by Toho and features special effects by Eiji Tsuburaya. It is also Tohos last Kaiju film to be shot in blackandwhite.

A rare species of butterfly native to Siberia is found in a mysterious valley in Japan, a pair of entomologists go to investigate. In response, an expedition is dispatched to their habitat, located along the Kitakami River, to discover why the insects might be living in Japan. Two members of the scientific community helm the expedition, but are mysteriously crushed by something that the police can only describe as powerful. The nearby villagers of the Kitakami River insist that the deaths were a result of the wrath of their mountain god BaradagiSanjin.A larger expedition is then dispatched to the area. This time the investigation is funded by the film company 20th Century Mysteries Solved, an organization that seeks to uncover the truth behind the two deaths to report on it. Staff of the firm are reporters Horiguchi and Yuriko, the sister of one of the men killed, and an entomologist named Kenji from the scientific community come along. ........

Source: Wikipedia