Oorn is a Great Old One and is the wife of the reptilian Mnomquah.

She has the form of a huge tentacled mollusk, with snaking appendages that can spew digestive fluid on things she wishes to consume.

Like her husband, her only true worshipers are the Men of Leng and the Moon-Beasts. A temple devoted to Oorn and Mnomquah is near Sarkomand in the Dreamlands.