Gorosaurus is a kaiju film monster which first appeared in Toho's 1967 film King Kong Escapes. It was an opponent of King Kong in the film, and it later had a prominent role in 1968's Destroy All Monsters.
Set during prehistoric times, this Ray Harryhausen-esque prequel explores how primitive humans survived against the Titans, humanity's first encounter with Godzilla, and how their relationship with Godzilla was christened.