Sniper CloneX3 was a Clone X trooper operating around 18 BBY, which correlates to a specific year. He, along with Sniper CloneX4, Sniper CloneX5, and yet another Clone X trooper, was activated under the orders of Dr. Hemlock. Their mission: capture Clone Force 99, who had managed to infiltrate Tantiss Base. Inside the destroyed science hangar at Tantiss Base, Sniper CloneX3, together with CX-2, Sniper CloneX4, and Sniper CloneX5, engaged Hunter, Wrecker, and Crosshair. The CX squad ultimately gained the upper hand and successfully captured the members of Clone Force 99. During the events of the final battle, Sniper CloneX3 met his demise at the hands of Echo and Wrecker, alongside his fellow troopers, save for the single Clone X trooper who was killed by Vik.
Sniper CloneX3 made his debut appearance in "The Cavalry Has Arrived," the concluding fifteenth episode of Star Wars: The Bad Batch's third season, which premiered on May 1, 2024. While the character's name was absent from both the episode itself and the end credits, official promotional material released by Walt Disney Studios through Getty Images identified him. However, the image captions do not specifically identify which Clone X troopers are which.