Satan

Satan is the horned personification of evil in many Human mythologies, and is of a similar form to many gods of other races such as the Draconians and the Kaleds, the latter having a horned god of war. (DW: The Satan Pit)

In reality, Satan has various origins in many species, such as the Dæmons, a horned race from the planet Dæmos, Sutekh of Phaester Osiris, and an ancient, unnamed race from the Pre-Universe, of which at least two members survived into this universe, The Beast and his son, Abaddon. (DW: The Daemons, Pyramids of Mars, The Satan Pit, TW: End of Days)