Unidentified B1 battle droid 4 (Umbara)

"Intruder alert!"

- The droid, realizing that the starships were controlled by clone troopers.

This battle droid was stationed in the hangar of a Separatist supply ship stationed over the planet Umbara during the Battle of Umbara.

Biography
When the Separatist supply ship was infiltrated by three Galactic Republic clone troopers flying captured Umbaran starfighters, the B1 battle droids aboard the ship realized that the starships were in fact controlled by clones and not Umbarans and opened fire on them with their E-5 blaster rifles. This droid was destroyed along with the supply ship when the clones destroyed the ship's reactor.

Behind the scenes
The B1 battle droid, like every battle droid in The Clone Wars movie and The Clone Wars TV series, was voiced by Matthew Wood. His name was never given.