CT-4040, nicknamed "Cutup", was a rookie clone trooper that appeared in the Star Wars: The Clone Wars episode "Rookies". He was among several inexperienced clone troopers assigned to a listening post on a moon in the Rishi Maze that served as the first line of defence for Kamino, the aquatic world where the Republic's clone troops were manufactured. Cutup and the other members of Domino Squad found their assignment especially boring, but that would change after a meteor shower fell near the outpost. However, two of the falling meteors were actually disguised CIS landing craft containing a squad of BX droid commandos.
After killing the sentry and using his armour as a disguise, the droid commandos infiltrated the outpost and opened fire, killing three of the troopers, including the Sergeant. Cutup, Fives, Echo and Hevy were the only ones to survive the droids' initial attack and snuck out of the base through a ventilation duct. Shortly after getting outside, the four troops were attacked by a Rishi eel. The creature grabbed Cutup in its maw and disappeared out of sight, most likely making a meal out of the unfortunate clone.