CT-782, nicknamed "Hevy", 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. Hevy 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.
Not long afterward, clone commanders Cody and Rex arrived for an inspection. Hevy managed to warn the officers by sending up a droid attack flare. The clones soon met Cody and Rex after they narrowly escaped a droid ambush. After meeting the clones for the first time, Rex demanded that the rookies remove their helmets to verify that they were clones. After the three rookie clone troopers obeyed and removed their protective headgear, a Rishi moon eel appeared and began to attack them. This time, Rex used his blaster to kill it with one shot to the eye, a feat that impressed the rookies.
The clones then formulated a plan to take back the listening post, regaining access by using the severed head of a commando droid and one of their helmets in order to fool the droids inside. Once the doors were opened, the troopers opened fire and gunned down all of the commando droids. After gaining access to the control room, they discovered that the base's transmitter was sending out an all-clear signal, a means of signalling General Grievous' fleet to attack Kamino while at the same time fooling the Republic fleets into thinking that nothing was wrong. The signal had been hardwired and could not be shut off, so the clones decided that they had to blow up the listening post to stop the signal and alert the Republic fleet. However, a battle droid battalion had been deployed to the moon after receiving no word from the commandos, giving the clones little time to execute their plan.
Using several thermal detonators and a tank of liquid tibanna, the clones put together a heavy explosive device to blow up the base. After holding off a wave of droids, the clones evacuated and Hevy attempted to detonate the bomb remotely, but the detonator switch didn't work and so he went back inside to set off the bomb manually, aware that doing so would result in his own death. Hevy gunned down several droids on his way to the control room, but after running out of ammo he was shot in the back. The droids advanced into the control room, curious as to whether they were meant to take prisoners, but Hevy used his last ounce of strength to reach for the panel on the bomb and set it off, blowing himself up along with the droids and the entire outpost.