Zathog (Dark Lord of the Whirling Vortices) a Great Old One who settled ain the heart of the planet Zarr in the Xentilx galaxy after fleeing from the war with the Elder Gods and their “overweening” sphere of infulence. He is one of the few gods still awake, and additionally still possesses its full powers (possibly because it moved to another galaxy, thus escaping the influence of the “star change”). He became the patron god of the Zarrians offering them rulership of the Universe in return for freeing the Old Ones, and the destruction of the Elder Gods (or Pain Lords ), even at the cost of all time and space. He is said to be Ubbo-Sathla's brother and seeks to unite life on Earth into the Oneness of Ubbo-Sathla once more. A reference to “Black Zathog, the master of the Zarrians” is made in the Necronomicon. The name is reminiscent of Zoth-Ommog .
Zathog was created by Crispin Burnham in conjunction with Richard L. Tierney; it as also been used by Llewellyn M.Cabos.