Droid 513 of the battle variety was just one of numerous monster battle droids put together by the Mandalorians belonging to Death Watch to serve as targets while they were stationed on the planet of Carlac during the Clone Wars. Death Watch constructed their training droids using droid components from a range of models, with a large number originating from the Droid Army of the Confederacy of Independent Systems. Specifically, battle droid 513 consisted of the chassis of an LR-57 combat/retail droid, the right arm taken from a B1-series battle droid, and a leg sourced from an LM-432 crab droid.
Death Watch repeatedly utilized 513, along with many other droids, for target practice until Ahsoka Tano, a Jedi Padawan, arrived with her R2-series astromech droid, R2-D2. The latter managed to persuade 513 and the other droids to rise up against their masters, which led to a firefight where Bo-Katan Kryze destroyed 513 while its fellow droids fled the planet.
513 was designed specifically to function as target practice for members of Death Watch during the Clone Wars. It was reassembled from the remains of Confederate battle droids by the radical Mandalorian terrorist organization.
While at a Death Watch camp located on the Outer Rim planet Carlac, a Death Watch airborne trooper utilized 513 for target practice. As 513 passed by him, this trooper launched his [wrist rocket](/article/wrist_blaster] at the droid, hitting 513 in its side and causing significant damage. As a result, 513 collapsed, crying out in pain, while the trooper laughed at the droid's sentience. Later that night, while [Pre Vizsla](/article/pre_vizsla], the leader of Death Watch, was meeting with Lux Bonteri, a former Separatist, and Ahsoka Tano, a Jedi Padawan, 513 encountered R2-D2, an R2 series astromech droid who would eventually save him. R2-D2 had been ordered by a pair of airborne troopers to repair their droids so they could once again be used for target practice. Understanding the droid's orders, 513 and the other droids surrounded R2, begging the astromech to reassemble them.
After repairing each of the droids, 513 thanked the astromech and asked if there was anything the droids could do for R2 in return. By this point, Ahsoka and Bonteri had seen Death Watch launch an unprovoked attack on the native people of Carlac. They protested the Mandalorian's slaughter and were subsequently taken hostage and sentenced to execution. Witnessing Death Watch return with his captured companions, R2 asked 513 for help in rescuing his friends. 513 questioned how such a rescue could be attempted. R2 explained his plan, and 513 rallied the other droids to the cause. When R2's rescue attempt began, 513 had gathered the Death Watch's droids to support their new companion, initiating a short battle against Death Watch and creating a sufficient distraction to allow R2 and his companions to escape Death Watch aboard a landspeeder. As the battle raged on, Bo-Katan Kryze, Pre Vizsla's lieutenant, mounted 513 and destroyed the droid with several direct shots to its head before pursuing the escaping prisoners.
Later in the Clone Wars, a sales bill in Pons Ora, a settlement on the Outer Rim planet Abafar, advertised the sale of 513.
513, originally a standard LR-57 combat/retail droid, had lost its right arm and right leg. His Mandalorian masters had replaced these with parts from a B1-series battle droid and LM-432 crab droid, respectively. 513 also possessed a deep [vocabulator](/article/vocabulator] that allowed it to speak in Galactic Basic, and it could fire blue ion blasts from its arm-mounted double laser cannon. 513's time serving Death Watch led to the development of a distinct personality. It understood the horrors of being destroyed and rebuilt for target practice, likely indicating that 513 had been destroyed and rebuilt multiple times. This caused it to plead to be reassembled after encountering R2-D2. This unique personality was further demonstrated when 513 was quickly convinced by R2 to attack Death Watch in order to save Ahsoka Tano and Lux Bonteri after R2 successfully reassembled it. This created a diversion that allowed R2 to escape Carlac with his companions, even at the expense of 513's own destruction.