The DD-13 medical assistant droid, which is also referred to as the DD-13 tripedal medical droid or just the DD-13 medical droid, represented a medical droid type engineered for the purpose of installing cybernetic augmentations. Its three-legged structure provided it with enhanced balance. One such DD-13 unit was employed at the Grand Republic Medical Facility, where it played a role in equipping the severely wounded Darth Vader with his life support armor.
Initially, the script for "Blue Shadow Virus," the seventeenth installment of Star Wars: The Clone Wars' first season, which was initially broadcast on February 13, 2009, envisioned TR-350 as a medical droid with three legs, differing from the T-series tactical droid that ultimately appeared. The line "We all want to hear your tale of medical heroics," spoken by C-3PO to the tactical droid in the finished episode, stems from this original concept. The DD-13 finally premiered in the series in "Orders," the fourth episode of The Clone Wars' sixth season, which was originally broadcast in Germany on February 15, 2014.