HISTORY: Several years ago, a discredited surgeon named Jonas Harrow came upon a dying gunman in an alley in the Bowery. The man was severely beaten and disfigured, and was delirious with pain. Seeing an opportunity to redeem his own reputation, Harrow took it upon himself to save the man's life. He took him to his laboratory and began operating on him. The operation went on for three full days during which most of the gunman's shattered bones were replaced with unbendable steel alloy, which gave his skull the peculiar shape of the head of a hammer. Thus the gunman became "Hammerhead".

The last thing Hammerhead had seen after he had been shot and prior to passing out, was a poster for a movie called "The Al Capone Mob". While he was unconscious, he dreamt about the movie poster and became obsessed with the gangster period of the 1920’s. Once he was miraculously healed by his savior, Hammerhead began wearing suits resembling those worn by gangsters in the 1920's and started a gang war against a criminal organization led by the infamous Doctor Octopus. It was during that same gang war that Spider-Man first encountered Hammerhead, who he defeated before any innocent people were killed. But the hammer-headed menace has resurfaced again and again, waging wars against such criminal masterminds as Norman Osborn, Silvermane, and the Kingpin, to name a few. His recent attempt to takeover the New York branch of the Maggia failed when he was defeated by Don Fortunato, who forced him to swear allegiance.

Hammerhead was last seen in the "Spider-Man: Lifeline" mini-series, where he waged a war against Caesar Cicero to obtain recently found fragments of the lifeline tablets to that he could save his dying sister from the cancer coursing through her body. Although he failed to use the tablet's powers to save his sister, Spider-Man concocted a special antidote that saved her life.