CT-19-7409, or "O'Niner" was a Clone Trooper Sergeant who served during the Clone Wars.
O'Niner completed training on Kamino, and fought in the Battle of Geonosis, and later the Battle of Celestial Wake. He was then stationed on the Rishi Moon to command the Rishi Outpost. All the men he commanded were rookies who had seen no combat, and were itching for a fight, especially since there was no excitement. Eventually though, the outpost was attacked by CIS Commandos. O'Niner sent "Nub" and CT-00-2010 to confront them. They were killed though, and O'Niner tried to send a message to the fleet. Unknown to him, the droids jammed the signal. Eventually, O'Niner was killed in the ensuing assault.