Almost nothing is known about the man inside the armored suit, but the Steel Slammer made his presence known during an attempt to get back at his rival, millionaire philanthropist Stewart Ronalds, when he stole a priceless piece of artwork that Ronalds loaned to the Idelson Museum of Modern Art. His debut was witnessed by Phil Urich, who was determined to put a stop to the Slammer’s criminal ways. As the Steel Slammer busted out of another museum after lifting a second sculpture Ronalds loaned out, Phil Urich, now in the guise of the Green Goblin, began tailing him. Once the Steel Slammer noticed his pursuer, he took him head on. Revealing to the Goblin that he was an industrial spy, and his rivalry with Ronalds went back a long way, including competing over the same companies and even the same woman, the battle came to an abrupt end when Urich threw the Steel Slammer into an oncoming train. The resulting pinball effect caused the Slammer to be bounced from building to building only to finally hit the ground defeated. The only thing that saved his life was the armored suit, and he cursed the Green Goblin as he flew away to return the second stolen sculpture. The police arrived shortly after, but it has yet to be revealed if the Steel Slammer escaped or was incarcerated.