Yig first appears in "The Curse of Yig" (1929), a collaboration between Lovecraft and Zealia Bishop. Robert E. Howard also incorporated the entity into his own fiction, linking it to the serpent-men of the Hyborian Age.
Depicted as a humanoid figure covered in scales, Yig punishes those who kill or mistreat snakes by transforming them into serpents or driving them to madness.