Cthulhu is a fictional cosmic entity created by horror author H. P. Lovecraft in 1926, first appearing in the short story "The Call of Cthulhu" when it was published in Weird Tales in 1928.
Cthulhu is one of the central Great Old Ones of the Cthulhu Mythos. It is often cited for the extreme descriptions given of its hideous appearance (which includes green skin, gargoyle wings and a squid shaped head), its gargantuan size, and the abject insanity inducing terror that it evokes on the persons unlucky enough to watch him.