The Hammer was a member of Don Vizioso's gang. Vizioso indicates that he is his best mob enforcer.
Hammer is tall and muscular Italian-American gangster, wearing sunglasses and toothpick usually, parodying Sylvester Stallone.
He appears after throws the smoke can to knock the Mutanimals out unconscious to free Vic and Vincenzo.
Later after turtles and Mutanimals come to the restaurant to confront Vizioso, Hammer manages to anger Leatherhead, with them escaped.
He comes back as in his armor to fight the Mutanimals, despite their best attempts, they all defeated. But thanks to Raph, they were able to defeat Hammer.
The Hammer was present with Don Vizioso when he had the Heart of the Shredder with him. In the Turtles' fight with Don Vizioso at his restaurant, the Hammer was defeated when the chandelier was dropped upon him. During the Turtles' next fight at Don Vizioso's hideout, the Hammer battled the Turtles, April and Karai until the battle was crashed by the Foot Clan and Kavaxas. The Hammer tried to fight Kavaxas only for his mech suit to be ripped apart followed by Kavaxas draining the Hammer's soul out of him, killing Hammer (that's the same method he did to Tatsu).
- Mech Suit - Hammer has a mech suit with rocket launchers, a gripping claw, and a hammer that he fights with.
- Hammer is a very on-the-nose parody of Italian-American actor Sylvester Stallone whom Eric Bauza also impersonates when voicing the Hammer.
- His catchphrase is: "Hey yo!"