Hammer was an ARC trooper who served in Rancor Battalion during the Clone Wars. Like all clones, he was born and bred on the rainy world of Kamino. When Rancor Battalion was called back to Kamino, Hammer was assigned to guard the cloning facilities at Tipoca City, alongside fellow ARC troopers Colt, Blitz, and Havoc. Hammer later fought in the Third Battle of Kamino when the Separatists invaded the city.
Hammer wore the experimental version of the Phase II clone trooper armor that was customized with red markings.
Hammer, Havoc, and Blitz took positions in the hanger with several other clones that were ready to attack the Aqua Droids. Even with Havoc's death, Hammer continued to fight against the invaders of his homeworld with Commander Blitz and the rest of the clones and managed to hold off the enemy until Shaak Ti arrived. With the help of the Jedi Master, Hammer and his clone brothers were able to push back the enemy forces. Hammer was last seen supervising the clean up of an area where Blitz was seen, also where Fives and Echo were given the honorary title of ARC trooper.
- It was initially thought that Hammer was ARC Commander Colt due to his limited screen time and similar design.
- In 2012, Lego released a Star Wars: The Clone Wars battle pack that featured an ARC Trooper mini-figure that, though unnamed, looks very similar to Hammer.
- ARC Troopers (First appearance)