The Brotherhood of the Beast is an ancient cult that worships one of the Outer Gods known as Nyarlathotep in his aspect as The Beast, and they are one of the many antagonistic groups featured in the Cthulhu Mythos genre by author H. P. Lovecraft. They first appeared in The Fungi from Yuggoth/ Curse of Cthulhu/ Day of the Beast campaign supplements to Call of Cthulhu. The Brotherhood is dedicated to fulfilling the prophecies of its founder, Nephren-Ka, an Egyptian high priest of Nyarlathotep in the 14th Dynasty.