A Clone X trooper operated within Tantiss Base circa 18 BBY of the standard year. Dr. Hemlock activated this Clone X trooper, together with Sniper CloneX3, Sniper CloneX4, and Sniper CloneX5, with the objective of apprehending Clone Force 99 after their infiltration of Tantiss Base. When Echo and a contingent of liberated clone prisoners appeared, the trooper was located within the Tantiss Base training room. Ultimately, the trooper met their death at the hands of Vik.
This Clone X trooper, a human clone derived from the bounty hunter Jango Fett, previously served as a clone trooper in the Galactic Republic's Army during the Clone Wars against the Confederacy of Independent Systems. During the skirmish on Wayland, the trooper was killed by Vik who shot them repeatedly as the trooper rounded a corner with their blaster raised.
The armor worn by the Clone X trooper resembled that of other members of CX squad. Uniquely, this trooper's helmet featured goggles, and they were equipped with a double-barreled blaster pistol.