Osogain is an Action Commander of Space Empire Zangyack and an antagonist in episode 18 of Kaizoku Sentai Gokaiger.
He is voiced by Dai Matsumoto, who also voiced Zan Vardo in Space Sheriff Gavan: The Movie.
Osogain was assigned by Damaras to set up a beachhead for a full Zangyack invasion on Earth. He led a force of Gormin in attacking a construction site to convert it into a Zangyack base, but his operation is met by Gai Ikari's intervention. Gai became Gokai Silver and initially fought Osogain's forces alone, but was joined by the other Gokaigers after they took an interest in him. He was defeated by Gokai Silver using the Gokai Supernova Final Wave. Osogain and six Sugormin units are then enlarged by Insarn, only to be destroyed by Goujyujin.