Demogorgon n. A mysterious, terrible, and evil divinity, regarded by some as the author of creation, by others as a great magician who was supposed to command the spirits of the lower world. See Gorgon. "Orcus and Ades, and the dreaded name Of Demogorgon."
... a lively interest throughout the journey. I met one of my fellow-passengers months after, driving a street tramway car in San Francisco; and, as the joke was now out of season, told him my name without subterfuge. You never saw a man more chapfallen. But had my name been Demogorgon, after so prolonged a mystery he had ... — Across The Plains • Robert Louis Stevenson