D4-R4B, nicknamed "Arforb," was an R4 astromech droid that served in the Massassi Group of the Alliance to Restore the Republic based in the Great Temple on the moon Yavin 4. One of dozens of Industrial Automaton's R-series astromech droids in the base's droid labor pool, D4-R4B had a programming glitch that made it afraid of flying. As such, the droid was not assigned starfighter duty, but excelled at ground maintenance to compensate for its shortcomings.
In 1 BBY, D4-R4B was stood in one of the Great Temple's hangars when the criminal Jyn Erso was escorted through the room by a member of the Alliance's military police. Soon after, the R4 unit was stood with fellow astromech R2-BHD beside a T-65 X-wing starfighter in the hangar when Erso was led back through by Alliance Intelligence agent Captain Cassian Andor before they departed for the moon Jedha. Sometime later, D4-R4B was stood in the mouth of the hangar as Erso and Andor boarded the stolen Imperial cargo shuttle SW-0608 in order to travel to the planet Scarif.
D4-R4B (right) did excellent maintenance work to compensate for its fear of flying.
D4-R4B was a grouchy droid, a trait that its fellow astromech R2-BHD found to be illogical. It felt great guilt over the bug that prevented it from aiding pilots in combat and so compensated with its excellent maintenance work on the ground. D4-R4B had white paneling with charcoal gray stripes and a black sensor. The droid's coloring matched that of the Imperial droid R4-M9. D4-R4B stood 1.15 meters (3 feet 9 inches) tall.
D4-R4B was created for the Anthology Series film Rogue One: A Star Wars Story, which was released on December 16, 2016. Prior to the film's release, the droid was revealed in the first teaser trailer for Rogue One, which was released on April 7, 2016. The astromech was first identified in the reference book Star Wars: Rogue One: The Ultimate Visual Guide, which was written by Pablo Hidalgo and released on the same day as the film.
- Star Wars: Rogue One: The Ultimate Visual Guide
- Rogue One: A Star Wars Story - The Official Mission Debrief
- Star Wars: Geektionary: The Galaxy from A - Z
- Star Wars: The Complete Visual Dictionary, New Edition