Mangog

Mangog, or "The Mangog" as it originally referred to itself, is the sum total of the hatred of a billion billion beings that were once killed by the ruler of Asgard and the Norse Gods, Odin. Imprisoned deep beneath Asgard, Mangog is accidentally freed by the Rock Troll Ulik, and goes on to wage war against Odin and the other Norse Gods on several occasions.