OOM-9 was an OOM command battle droid that led the Droid Army of the Trade Federation during the Invasion of Naboo. After Jedi MasterQui-Gon Jinn and his apprentice returned from Coruscant with Queen Amidala and gained the help of the Gungan Grand Army, OOM-9 was sent, with the Federation’s battle droidarmy to destroy the gungans. He oversaw the battle while inside his own personal Armored Assault Tank and the droids were able to create a victory for the Federation, but this was short lived, as every Federation battle droid was shut down when Anakin Skywalker destroyed the Droid Control Ship above Naboo. The control ship’s destruction affected OOM-9, as it rendered the droid commander temporarily inactive.
While Star Wars: The Complete Visual Dictionary, New Edition states that OOM command battle droids and other OOM-series battle droids are predecessors to the B1-series battle droid line, Ultimate Star Wars and Ultimate Star Wars, New Edition state that OOM-9 is a B1. Because both Ultimate Star Wars books and the majority of other canon sources treat OOM units as part of the B1 line, this article assumes The Complete Visual Dictionary is incorrect.