Terochilus was a Kaiju that appeared in episodes 16 and 17 of Return of Ultraman.

A mysterious ancient flying Kaiju from the Cretaceous period, Terochilus first appeared flying over a group of party going teens, knocking many into the water moments before the ship exploded from a bomb strapped to it. Later, the monster assaulted and destroyed a plane, attracting attention of MAT. They soon went searching for the avian kaiju, finding it flying over the city, spraying webs and cocooning a building. The air force soon attacked the monster but he simply knocked them out of the sky and fled, leaving MAT wondering why he targeted this building in particular.

Later that day, a toxic red gas began being released from the building, choking civilians, similar to a gas that had previously been used during an attempt on Go's life. Even stranger, it began to snow for no known reason! While going out to sea in search of the of Terochilus, Go found an island where a volcanic eruption was taking place, at the top discovering Terochilus in the caldera, spraying his webbing, which was actually the "snow" that had been coming down.