Army B served as a military division within the Trade Federation Droid Army. During the Invasion of Naboo in 32 BBY, its mission was to outmaneuver the Gungan Grand Army at the Battle of Grassy Plains. While attacking a base held by the Naboo Resistance, Army B met its end.
Star Wars: Starfighter, a video game released in 2001, featured Army B. Subsequently, the reference book The New Essential Guide to Vehicles and Vessels included a depiction of the Battle of Grassy Plains that specifically identified this unit.