Hastur

Hastur "the Unspeakable" (also called Xastur and Asatur) is a Lovecraftian Primeval god whose figure was notably extolled by August Derleth, who considered him "offspring of Yog-Sothoth" and "half-brother of Cthulhu".

Contrary to popular belief, Hastur was not created by Lovecraft. Hastur was conceived by the writer Ambrose Bierce in his story Haîta the Shepherd. Hastur's first appearance in The Cthulhu Mythos was a mention in the story The Whisperer in the Dark, the only story written by Lovecraft in which his name appears.