Zoth-Ommog, also known as The Dweller in the Depths, is a Great Old One who appears in the H.P. Lovecraft-inspired Cthulhu Mythos.
Vaguely cone-shaped, Zoth-Ommog is said to have four sucker-lined arms similar to those of a starfish, a tooth-filled maw resembling that of a theropodian dinosaur, and a great mane of tentacles. It is primarily a water-dwelling creature, known to spend its time crawling across the bed of the ocean.
It is known to be worshiped by the Yuggs, a race of subterranean creatures resembling enormous flatworms.
The third "son" of Cthulhu and Idh-yaa, Zoth-Ommog was spawned untold aeons ago in the binary star system of Xoth along with its siblings Ghatanothoa, Ythogtha and Cthylla; when Cthulhu relocated to Earth he took his progeny with him. After defeat in the long war with the Elder Gods, it was imprisoned beneath the seabed near its father's tomb, somewhere in the vicinity of dead R'lyeh.
In the modern age, Zoth-Ommog has created avatars which take the form of sentient statues. He uses these statues to cast his will into the dreams of men in much the same manner as his father. One of these, dubbed the Ponape Figurine, resided in the Sanbourne Institute of Pacific Antiquities for a time before being destroyed by the power of a star stone.
- Out of the Ages (1975), by Lin Carter.
- The Transition of Titus Crow (1975), by Brian Lumley.
- The Horror in the Gallery (1976), by Lin Carter.