Roan (ラドン, Radon?) is a fictional monster, introduced in Rodan, a 1956 release from Toho Studios, the company responsible for the Godzilla series. Like Godzilla and Anguirus, it is designed after a type of prehistoric reptile (The Japanese name "Radon" is a contraction of "pteranodon " and may also have been chosen to suggest radiation). Radon is usually referred to as Rodan in the United States, possibly to avoid confusion with the atomic element Radon; also, anytime his name is written in English in Japan, it is written as Rodan. He is occasionally portrayed as enemy of Godzilla but has allied himself with the King of Monsters on several instances against more dangerous threats.