Xenu

Xenu is the alien god of Scientology. He is the dictator of the Galactic Confederacy. According the the scriptures of Scientology, over 75 billion years ago, he brought the people to Earth and set them all up in volcanoes and then killed them with some nuclear hydrogen bombs. He appeared as a character in South Park, in the episode Trapped in the Closet.

Appearance
Xenu is a gray alien creature with a gothic red suit. Xenu has glowing yellow eyes and thin black eyebrows. Xenu has a bunch of tiny gray tentacles on his head and a flap over his mouth that wiggles when he makes noise. Xenu's arms are gray tentacles.