Cthulhu

That is not dead which may eternal lie
For with strange aeons, even death may die

Cthulhu is the big bad from H.P. Lovecraft's short story "The Call of Cthulhu". Worshipped as a god by cultists, role-playing gamers, computer geeks, and other deranged people, Cthulhu is in fact an alien, and High Priest to even bigger nasties known as the Elder Gods. Weaker minds go mad just looking at him, and it is said one day he will rise from his eternal slumber in the sunken city of R'yleth and bend the world to his will. In other words, he's not the sort of guy you'd want to meet in a dark alley. But because his face looks like a squid, he fits in just fine with other animutation characters.