2. Cathulhu (The Real Ghostbusters)
Winston Zedmore: "Cathulhu? I've heard of him. He's bad, right?"
Egon Splengler: "He makes Gozer look like Little Mary Sunshine." Except he really didn't. Cathulhu (sometimes spelt Cthulhu) - a Lovecraftian monster - is generally depicted as a cosmic entity who has power beyond mortal comprehension and is able to nearly instantly regenerate his body if it is ever damaged (the wound will heal faster than the wound is made). He has destroyed countless worlds and is usually larger than any mountain - being able to stand up in even the deepest oceans and still have his head above the surface. He has also, in some fictional sources, shrugged off nuclear weapons as if they were nothing and is sometimes depicted as being the source of the universe's evil and all bad feelings in existence. In Ghostbusters, Cathulhu was sent back to the depths of the ocean when the titular heroes used their particle streams to ionize a roller coaster track in Coney Island, causing lighting to strike it, effectively sending 100 Giga Volts of electricity though it. While this wasn't enough to cause any lasting injury, it was enough to return it to a dormant state, which is a far cry from shrugging of a nuclear attack.