General "Thunderbolt" Ross's obsession with destroying the Hulk led him to undergo gamma ray treatments himself, transforming him into the fearsome Red Hulk. With all of the Hulk's strength, plus energy-absorption and heat generation, he went mad with power and attempted to rule the country. After realizing he has become what he hated most, he now seeks redemption as an Avenger.
Current Version:
Red Hulk (Modern)