hastur

Hastur, He Who Must Not be Named, the King in Yellow. A Cthulhu_Mythos deity who is very easy to summon-simply chant his name three times-but gets extremely cross if his time is wasted, so be certain to have a sacrifice and request ready-or at least, his favorite play, "The King in Yellow" ready to roll (but beware, reading the script-which, apparenty, is the account of how he destroyed the magical kingdom of Carcosa and drove its queen Cassilda crazy-is known to drive people insane). Appears as a tentacle monster wearing a yellow robe.

While he is the father of Shub-Niggurath's children, he apparently stiffed her on child support. The two deities, their cults, and servant races, hate each other immensely.