CT-8508 was a clone trooper who later transitioned into a stormtrooper. Cloning technology on the planet Kamino was used to create him, and he went on to serve the Galactic Empire throughout its reign. Under the leadership of Clone Commander CT-9904, also known as "Crosshair," he was deployed to the junk planet Bracca with the mission to locate Clone Force 99, famously known as the "Bad Batch." Upon his arrival on Bracca, CT-8508 was tasked with securing the Bad Batch's Omicron-class attack shuttle, known as the Marauder.
After discovering that the Marauder was unoccupied, CT-8508 informed Crosshair of this fact. The commander then instructed him to establish a security perimeter around the shuttle's location. However, the bounty hunter Cad Bane soon killed him and his stormtrooper squad; Bane had arrived to capture a member of the Bad Batch. Another trooper tried to contact CT-8508 to inquire about the status of the Marauder, but received no response.
Born via cloning on the world of Kamino, CT-8508 eventually became a stormtrooper and enlisted in the Stormtrooper Corps of the Galactic Empire during its rule, which commenced in 19 BBY. Around that time, CT-8508 was dispatched under the direction of the distinguished Stormtrooper Commander CT-9904 "Crosshair" on a deployment to the scrapyard planet of Bracca to track down the renegade clone squad Clone Force 99, otherwise known as the "Bad Batch." The taskforce traveled to Bracca aboard three Nu-class attack/transport shuttles and touched down near a destroyed Venator-class Star Destroyer where the Bad Batch had been sighted by the local Scrapper Guild.
The clone stormtroopers organized themselves into rows of five in front of the Nu-class shuttles; CT-8508 stood in front of his own unit as Crosshair and his elite team exited one of the transports. After evaluating the Bad Batch's situation, the commander instructed CT-8508 to lead a group of clones to locate the Batch's personal ship, the Omicron-class attack shuttle called the Marauder. The stormtrooper acknowledged the order and signaled his troops to board a Nu-class shuttle, which then departed to locate the Marauder once the clones were aboard.
CT-8508 and his fellow clone stormtroopers quickly located the Marauder and conducted a search of the shuttle, only to find it empty. The stormtrooper then contacted Crosshair, reporting his findings. The commander then ordered him to secure the perimeter, which CT-8508 acknowledged. However, CT-8508 and his clone comrades were ambushed by the Duros bounty hunter Cad Bane, who was attempting to capture the Bad Batch's youngest member, Omega. Bane killed the entire clone unit guarding the Marauder, leaving CT-8508 lifeless at the base of the shuttle's boarding ramp.
As the Bad Batch members approached their shuttle, a clone stormtrooper with Crosshair attempted to contact CT-8508 for a status update, but received no response from the fallen trooper. When Sergeant "Hunter" and Omega of the Bad Batch arrived at the Marauder they found Bane and the dead troopers. The bounty hunter mocked how easily he was able to eliminate the clone troopers, before injuring Hunter and abducting Omega. The remaining Bad Batch members soon arrived and brought the sergeant aboard their shuttle, escaping from Bracca.
As a clone derived from the human male bounty hunter Jango Fett, CT-8508 stood at a height of 1.83 meters and possessed tan-colored skin. He consistently acknowledged and obediently followed all of Crosshair's directives, relaying to the commander any new information he obtained.
CT-8508 wore white Phase II clone trooper armor and carried a DC-15A blaster carbine. He also utilized a comlink integrated into his helmet.
CT-8508 was featured in "Reunion," the eighth episode of the Disney+ animated series Star Wars: The Bad Batch, which premiered on June 18, 2021. He was voiced by Dee Bradley Baker, who provides the voice for every clone trooper in The Bad Batch as well as other animated series including Star Wars: The Clone Wars.