Cthulhu is a fictional cosmic entity created by writer H. P. Lovecraft. It was introduced in his short story "The Call of Cthulhu", published by the American pulp magazine Weird Tales in 1928. Considered a Great Old One within the pantheon of Lovecraftian cosmic entities, this creature has since been featured in numerous popular culture references. Lovecraft depicts it as a gigantic entity worshipped by cultists, in the shape of a green octopus, dragon, and a caricature of human form. The Lovecraft-inspired universe, the Cthulhu Mythos, where it exists with its fellow entities, is named after it.

"The Call of Cthulhu" is a short story by American writer H. P. Lovecraft. Written in the summer of 1926, it was first published in the pulp magazine Weird Tales in February 1928.