Wanting to discover the cause of the immense strength humans develop during moments of intense emotion, such as rage or fear. He experimented on himself as part of his research, but an accident caused him to receive an overdose of radiation.
The overdose of gamma rays caused a mutation in his brain. Now whenever he gets angry or outraged a startling metamorphosis occurs. John turns into a monstrous being of incredible strength; a creature driven by pure, mindless rage.
Believed to be dead (murdered by the creature), John now wanders Retroland - avoiding both the law and the media - as he searches for a cure for his condition.
Frantic and alone John endures to find a cure to get rid of the Hulk.
The Hulk possesses the potential for near limitless levels of physical strength depending directly on his emotional state, particularly his anger. He is also extremely resistant to physical damage, psychic assaults, temperature extremes, and is completely immune to disease and poisons. He can breathe underwater, survive unprotected in space, and when injured, heals from almost any wound within seconds. His powerful legs allow him to leap into lower Earth orbit or across continents. His durability, healing, endurance, and possibly speed, likewise increase in relation to his temper. He also has certain mental powers, which allow him to "home in" to his place of origin in Toronto, and to see and interact with astral forms.
He has been described as "possessing a mind so brilliant it cannot be measured on any known intelligence test