Cthulhu is a cosmic entity and one of the Old Gods, the first of The Dark Ones. Cthulhu is describe as a giant being with a squid-like face, bat-like wings and claws. Many years ago in ages long past, Cthulhu try to destroy the Multiverse cause of his hatred for all creation. He would've succeed haven't The Council of Light stopped him. Cthulhu was then imprisoned in the underwater city of R'lyeh where he sleeps for all eternity. According to legend, if Cthulhu breaks free from his prison, it's the beginning of the end of the Multiverse.