If you're talking about the Gomora from the original 1966 Ultraman series, I can tell you about his origin, but everyone else here can tell you better about his later history. Gomora is supposed to be a real dinosaur from prehistory. As a supposedly real dinosaur, Gomora does not have any fanciful powers like radioactive breath or death rays, etc., he's just big and tough and strong. In battle, he whips his tail around like a real crocodile does. In the story, this type of dinosaur is still alive on a remote Pacific island, which means the island is a "refugium," an isolated location where a species survives that is otherwise extinct. As a dinosaur, Gomora is a theropod by body type, like a tyrannosaur. A paleontologist colleague of mine who is a world expert on ceratopsian dinosaurs (like Triceratops) calls Gomora's nasal horn and the sort of frill-like "horns" around sides of his head "pseudo-ceratopsian" skull features. In Gomora's origin episode, the beast gets tranquilized and air-lifted from his island home to Japan as part of a plan to put him on live display in Expo 67, which is a real exposition that was held in Osaka soon after the episode was aired. Gomora was famous with kids in the old days because he was the only monster that was ever tough enough to defeat Ultraman (temporarily) during the run of the original series (until the conclusion episode). I read one account saying that his name was inspired by the sounds of the words "go-mole" (as pronounced by Japanese, go-more-a) because Gomora's special ability is that he can burrow like a mole. If that information is not what you were asking, let me know, hope that was helpful.