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. Mangog proves to be physically unstoppable, and is usually only defeated by exploiting Mangog's dependence on psychic energies (such as hatred, fear, or feelings of devotion) felt by other sentient beings to sustain itself. Without such a source, Mangog shrinks to near nothingness.
While usually acting independently, Mangog also assists the Titan Thanos in a quest for universal domination, but is ultimately stopped by the Thunder God Thor. Thor eventually ends the threat of Mangog entirely: having inherited the Odin Force, Thor simply dissolves an attacking Mangog with a wave of his hand. Mangog has not been seen since the destruction of Asgard.
Mangog possesses various superhuman physical and energy manipulative abilities.
Mystical and Psionic Energies: Mangog's draws any and all of his superhuman powers from the mystical and psionic energies that are manifested in the hatred and desire for vengeance that are felt by himself or by others.
Superhuman Strength: Mangog possess vast superhuman strength, the full limits of which aren't known. However, his physical strength easily rivals and exceeds that of Thor. Hence, he can ultimately lift far in excess of 100 tons.
Superhuman Speed: In spite of his great height and body mass, Mangog is capable of running and moving at speeds that are beyond the physical limits of the finest human athlete.
Superhuman Stamina: Mangog's advanced musculature produces no fatigue toxins during physical activity. As a result, as long as he is able to psionically feed off the energy manifested by vengeful thoughts, he possesses an limitless physical stamina.
Superhuman Durability: Mangog's body is far harder and more durable than the body of an Asgardian God. His body is highly resistant to all forms of conventional injury. He can withstand powerful impact forces, exposure to extremes of both temperature and pressure, falls from tremendous heights, and tremendously powerful energy blasts without sustaining injury.
Superhuman Agility: Mangog's agility, balance, and bodily coordination are all enhanced to levels that are beyond the natural physical limits of even the finest human athlete.
Superhuman Reflexes: Mangog's reflexes are similarly enhanced and are superior to those of the finest human athlete.
Energy Manipulation: Mangog is able to manipulate vast amounts of mystical energy for numerous purposes, though they're used almost always for destructive purposes. The most commonly seen of these include the ability to manipulate most substances on a molecular level and to fire massively powerful blasts of concussive force from his hands.
* Heightened Energy Projection when accessing Asgardians' life energies
Although Mangog has had no training in combat, the sheer scope of his physical and energy manipulative capabilities make him a highly formidable combatant, even against beings as powerful as Thor and Odin.
Mangog's powers, in fact his very life itself, is connected to the energies that he feeds from. Mangog will shrink or seemingly vanish if deprived of those mystical and psionic energies.
The exact nature of the Mangog has never actually been revealed and is unclear. He has often been called a demon, suggesting that he is a supernatural being parasitically dependent on the mystic and psionic energies of other sentient beings. It is also possible that Mangog is a minor abstract entity incarnating the hatred felt by the alien race, and later, by himself. In that case he may be an avatar of the conceptual entity Hate in a way that is similar to the relationship between the godlike entity Cytorrak and the Juggernaut.