OOM-9 was deactivated on Naboo, but his head was secretly taken off world with some other droids. In the Clone Wars, OOM-9 was reactivated, and was initially head of the Confederate Army. At, Geonosis, however, he was forced to flee. On Raxis Prime, he found the Force Harvester for Count Dooku. It was here he became head of the Confederate army, a title he lost after his failure to defend the Dark Reaper. OOM-9 went with General Grievous to Hypori, and had fair success, until a small group of surviving Jedi destroyed his tank, and ended his life. Rumor persists that OOM-9 tried to kill General Grievous on Hypori. He sent a group of battle droids after Grievous, to no avail. Grievous destroyed them, and if the rumor was correct, OOM-9 with them.