An ancient, dinosaur-like monster, Gomora is characterized by a large, crescent-shaped horn on its head and a long, thick tail. Its entire body is brownish, and its abdomen is covered in thorn-like protrusions.

Professor Nakaya discovered Gomora on Johnson Island while searching for fossils of the "Gomorasaurus," a dinosaur that had been extinct for 150 million years.

To exhibit Gomora at the World Expo, the SSSP tranquilized the monster, which was weakened by its prolonged sleep, with an anesthetic dart.
However, the anesthetic wore off during the airlift. Gomora began to struggle and, from the impact of falling to Mt. Rokko from a height of 2,000 meters, regained its inherent ferocity and powerful life-force.

In a battle with Ultraman in Osaka, Gomora initially defeated Ultraman with its powerful Mega-ton Tail attack.
Although it continued to reappear, its whip-tail was severely damaged by the SSSP’s Mars 133, prompting it to retreat by burrowing underground.

Gomora later appeared at Osaka Castle and went on a rampage. Finally, Ultraman broke Gomora’s crest and nasal horn before destroying it with the Spacium Beam.

Having been taken from the depths of slumber on an isolated island for selfish human reasons and ultimately killed, the SSSP sympathized with Gomora. A proposal was then made to have its body stuffed and exhibited at the World Expo.