Cthulhu is a gigantic deity.
 It was first introduced in his short story "The Call of Cthulhu", published by the American pulp magazine Weird Tales in 1928
:256According to Derleth's scheme, "Great Cthulhu is one of the Water Elementals" and was engaged in an age-old arch-rivalry with a designated air elemental, Hastur the Unspeakable, described as Cthulhu's "half-brother

