'Giant Monster Varan') is a 1958 Japanese kaiju film directed by Ishirō Honda, with special effects by Eiji Tsuburaya.

Produced and distributed by Toho Co., Ltd, it stars Kōzō Nomura, Ayumi Sonoda, and Koreya Senda, with Haruo Nakajima as Varan.

In the film, a reporter's investigation into two mysterious deaths in Japan's mountains leads to the discovery of a giant lake monster, wrecking its way towards civilization.

A heavily localized version, with new footage starring Myron Healey in the lead, was released in the United States on December 12, 1962 by Crown International as Varan the Unbelievable.

[3] Two scholars are sent to a region known as the "Tibet of Japan" to study rare butterflies, but they are killed by a landslide triggered by a massive creature.

Reporter Yuriko, sister to one of the late scholars, travels to Iwaya Village with scientist Kenji and another colleague to investigate the casualties, after the media pins the blame on a local spirit called “Baradagi”.

After finding the boy, a giant reptilian monster, whom Kenji identifies as "Varan", surfaces from a nearby lake and attacks the village, crushing the priest in the process.

Back in Tokyo, Dr. Sugimoto adds that Varan is a Varanopode, a creature that lived during the Triassic, Jurassic, and Cretaceous periods.

While the Air Force and Navy search for Varan, Sugimoto joins Dr. Fujimura and other scientists to discuss how to defeat the monster.

[4] At AB-PT's request, Toho planned for Varan the Unbelievable to be filmed in three parts, 30 minutes each, and with fade ins/outs for commercial breaks.

[1][6] Kuronuma was approached by Tanaka to write a new kaiju film, stating, "Rodan had arrived in the US, and a request for another came from [America] to Toho.

Honda noted that they couldn't start over and had to resort to "blowing up" the film to widescreen format, a method that was used for the Japanese release of Godzilla, King of the Monsters!

A new story was written by Sid Harris which featured an American military scientist stationed in Japan conducting a de-salinization experiment on the lake where Varan dwells.

[11] The American version runs at 70 minutes and was theatrically released on December 12, 1962 by Crown International, under the title Varan the Unbelievable.

These reports claim that Ifukube recorded a separate score between August 27 and 29 for the television version and a test print with three reels was shipped to Toho International in Los Angeles.

[5] In a contemporary review, Variety referred to the film as an "uninspired monster meller for saturation supporting niches" after Godzilla, Gorgo, and Dinosaurus!

[10] Tokyo Shock released the original Japanese version on DVD in the United States on May 10, 2005 under the title Varan the Unbelievable.