A lowlife from the beginning, Leon Shappe was the type of criminal that professionals avoided and nobody else trusted, thanks to his big mouth and a street drug called snap. Snap made him jittery and unreliable, to the point where he would betray his own mother for a single dose. Stealing purses and robbing the elderly just barely enabled him to make a living, was well as working as a snitch for the police. One day, one of his long-time buddies told him of an inventor who had created an armored mobile combat suit that would turn anyone into a one-man army.

Murdering the inventor, Leon stole the suit, thinking about selling it to the highest bidder. However, he realized he could make more money by using it himself. For perhaps the first time in his life, Leon thought about his own future. He became a professional assassin and called himself Speedfreek. But even with the suit, things weren’t much better. His drug habit made him unreliable, and he rarely was hired to do anything of importance. At a charity event, Leon met the Hulk for the first time. Hired to kill a young man under the wing of Jim Wilson and Rick Jones, Speedfreek fired an Adamantium tipped coil, which punctured the Hulk’s tough skin and held fast. However, due to the Hulk’s strength, the Jade Giant eventually gained enough traction to free himself and punch Speedfreek unconscious.

Leon eventually learned that his daughter, the one person in the world he loved more than his addiction to snap, was inexplicably killed. Disguising himself, Leon hired the Hulk to find the one responsible and bring him to justice. Unaware of who had hired him, the Hulk led Shappe to his daughter’s ex-boyfriend, who claimed her death was an accident. After a lengthy battle and nearly being disemboweled by Speedfreek’s Adamantium blades, the Hulk prevented Leon from getting his revenge and turned the boy over to the authorities.

Speedfreek eventually escaped from Ryker’s Island and teamed with Cobalt Man, Coldheart and Nitro. The New Warriors tracked them down intending to capture them on TV for ratings. Nitro used his powers to cause a tremendous explosion, resulting in the death of nearly all of the New Warriors, Coldheart, Cobalt Man and presumably Speedfreek as well.