Byatis, the Serpent-Bearded, the god of forgetfulness, came with the Great Old Ones from the stars, called by obeisances made to his image, which was brought by the Deep Ones to Earth. He may be called by the touching of his image by a living being. His gaze brings darkness on the mind; and it is said that those who look upon his eye will be forced to walk to his clutches. He feasts upon those who stray to him, and from those upon whom he feasts he draws a part of their vitality.

Byatis appears to posses one eye like a Cyclops, and had claws like unto a crab, a nose like the elephants that it is said can be seen in Africa, and great serpent-like growths which hung from its face like a beard, in the fashion of some sea monster. Basically the creature is depicted as incredibly large, one of its face tentacles is as thick as a man, which makes it about the size of the castle that it is trapped beneath. Byatis can be repelled by the Elder Sign.