Cthulhu Mythos species

This is a list of fictional creatures from the Cthulhu mythos of American writer H. P. Lovecraft and his collaborators.

Byakhee

The byakhees or byakhee birds first appeared in Lovecraft's short story "The Festival" and were later featured in August Derleth's tale "The House on Curwen Street." They are the servants of the Great Old One Hastur.

Lovecraft provides a description of the byakhees in "The Festival":

Out of the unimaginable blackness beyond the gangrenous glare of that cold flame, out of the tartarean leagues through which that oily river rolled uncanny, unheard, and unsuspected, there flopped rhythmically a horde of tame, trained, hybrid winged things that no sound eye could ever wholly grasp, or sound brain ever wholly remember. They were not altogether crows, nor moles, nor buzzards, nor ants, nor vampire bats, nor decomposed human beings; but something I cannot and must not recall. They flopped limply along, half with their webbed feet and half with their membranous wings; and as they reached the throng of celebrants the cowled figures seized and mounted them, and rode off one by one along the reaches of that unlighted river, into pits and galleries of panic where poison springs feed frightful and undiscoverable cataracts.

Deep Ones

The Deep Ones first appeared in Lovecraft's novella The Shadow over Innsmouth (1931), but were already hinted at in the early short story "Dagon". The Deep Ones are a race of intelligent ocean-dwelling creatures, approximately human-shaped but with a fishy appearance. They regularly mate with humans along the coast, creating societies of hybrids.

Numerous Mythos elements are associated with the Deep Ones, including the legendary town of Innsmouth, the undersea city of Y'ha-nthlei, the Esoteric Order of Dagon, and the beings known as Father Dagon and Mother Hydra. After their debut in Lovecraft's tale, the sea-dwelling creatures resurfaced in the works of other authors, especially August Derleth.