Quyagen is the god of Yagothoggua, mentioned in The Black Book of the Skull. The Great Old One is an enormous shadowy, horned creature with a mass of tentacles. He is served by the Y'nathogguans. The god is worshipped by blood sacrfices, most famously through the "brides of Quyagen". It used the Eye of Zysl'm against the Great Race of Yith until it was imprisoned under the temple at Yagothoggua. It might be related to Othuyeg.