Sinker, a Clone Sergeant, distinguished himself within the Grand Army of the Republic during the extensive Clone Wars. Alongside the rest of the Wolfpack, he participated throughout the entire conflict. In the 104th Battalion, he held the rank of sergeant, reporting to both Jedi Master Plo Koon and Commander Wolffe.
Sinker, similar to all clone troopers within the Grand Army of the Galactic Republic, originated as a clone from the genetic material of bounty hunter Jango Fett on the planet Kamino. He was designated a sergeant within the 104th Battalion, also recognized as the Wolfpack Battalion. This battalion was under the command of Clone Commander Wolffe and the Jedi Master, who also held the rank of General, Plo Koon, a member of the esteemed Jedi High Council.
In the early stages of the Clone Wars, Sinker accompanied Wolffe, Boost, and Clone Corporal Comet on a mission to penetrate the defenses of the Nexus, a Separatist-controlled floating city and trading hub. Their presence was detected by Wat Tambor, who subsequently destroyed the city. Despite the mission's failure, they successfully rescued civilian and were extracted by Koon.
During the pursuit of the Separatist superweapon known as the Malevolence, Sinker, along with Commander Wolffe, Boost, and Jedi Master Plo Koon himself, made their escape from Jedi General Plo Koon's Jedi Attack Cruiser in a Republic escape pod. This occurred after the cruiser sustained a direct hit from an ion cannon, resulting in a complete power failure and leaving it vulnerable. When their escape pod came under attack by numerous rocket battle droids and their pod hunter, Koon guided the sergeant and Boost in a successful defense of their pod, holding out until General Anakin Skywalker and Commander Ahsoka Tano arrived to rescue them. This rescue allowed the Republic to glean enough intelligence from the survivors about the ship to ultimately destroy the Malevolence.
Later in the conflict, Sinker, as part of the Wolfpack, participated in a covert operation alongside Ahsoka Tano to scale the walls of a Separatist stronghold on Felucia. During this mission, Tano was captured by the Trandoshan hunter Lo-Taren. General Anakin Skywalker, intent on finding his missing padawan, dispatched Sinker and other members of the Wolfpack to search the area surrounding the outpost. Despite multiple searches, they were ultimately unsuccessful and eventually departed.
During their inaugural mission while equipped with Phase II armor, Sinker and the Wolfpack were deployed to the planet Aleen alongside R2-D2 and C-3PO to provide assistance to the inhabitants following a series of earthquakes. Boost and Sinker accompanied R2-D2 to the Aleen mainframe station, where the droid downloaded Republic tools onto their systems. Once R2-D2 initiated the download, the two clones returned to support their Commander. As they departed the planet, Wolffe informed Sinker and Boost that they would be leaving the droids with Jedi General Adi Gallia, a prospect that Sinker found highly agreeable.
Sinker's service continued within the Wolfpack, under the leadership of General Plo Koon and Commander Wolffe, during a mission to the moon of Oba Diah. The Jedi Council, responding to a distress signal originating from Jedi T-6 shuttle 775519, dispatched Koon and the 104th Battalion to conduct an investigation. Sinker, operating the scanners of a clone turbo tank, successfully pinpointed the shuttle's location after detecting a weak signal amidst a severe sandstorm. The shuttle was identified as belonging to the deceased Jedi Master Sifo-Dyas.
Almost twenty years following the conclusion of the Clone Wars, Wolffe and former clone commando Gregor participated in the Liberation of Lothal from the control of the Galactic Empire. During this conflict, the native loth-wolves of Lothal joined the fight against the Imperial forces. Gregor, observing the resemblance between the wolves and the "Wolfpack" nickname for Wolffe's squad in the 104th Battalion, remarked that Wolffe had his Wolfpack back. Wolffe responded by noting that they fought with the same spirit as Sinker and his other comrades.
Like the majority of Jango Fett's clones, Sinker's height was 1.83 meters (6 feet), with tan skin and brown eyes. Notably, his hair was gray. Sinker was known for possessing a sense of humor and frequently made jokes, even in the most challenging situations. He also displayed mechanical aptitude, assisting in the rewiring of his escape pod after it lost power due to the Malevolence's ion weapon.
Sinker demonstrated skill with a jetpack, utilizing it to ascend the walls of a Separatist outpost on Felucia and on Kadavo. He was a proficient pilot, having flown an Aggressive ReConnaissance-170 starfighter on at least one occasion. Like many clones, Sinker became highly skilled in both armed and unarmed combat, as well as military strategy. He effectively applied these skills as a sergeant in the Wolfpack, notably during the hunt for the Malevolence and the Battle of Felucia, where he destroyed numerous droids.
Sinker was equipped with Phase I clone trooper armor during the hunt for the Malevolence and the engagements on Felucia. By the time of the earthquakes on Aleen, he had transitioned to Phase II clone trooper armor. Sinker customized both versions of his armor with Wolfpack insignia. On several missions, Sinker employed a jetpack to ascend vertical surfaces. Throughout the Clone Wars, Sinker's primary weapon was the DC-15A blaster carbine.
Dee Bradley Baker voiced Sinker, as well as all other clone troopers, in the animated TV series Star Wars: The Clone Wars. Sinker's character model was revised three times throughout the series.