ARC-0422 or "Gamma" was a Clone Trooper Commander in the Grand Army of the Republic. Gamma was sometimes given the nickname "Grammar" because he always had to be grammatically correct if someone got any word wrong. Gamma sometimes worked along with clone group Golden Squad. Gamma had the best training in the Army because he was always on the move. He never took a break when he was on duty or during battle. During his training on Kamino he was exposed to Gamma Radiation which gave him the name "Gamma". Although Gamma radiation isn't dangerous it wasn't dangerous for Gamma, because he already had a dose when he was just a DNA cell. Gamma was killed on Fleucia.