The B4 saber battle droid was the droid creation of the Gishi captain within the Confederacy of Independent Systems known as Lack Toler. Toler introduced his lightsaber wielding battle droid to the Republic in 20 BBY on the small moon of Ootoo IV, where he pitted the first two prototypes against Jedi Master Doola Karnt. Doola destroyed the first droid, and her clone commander, Commander Res, destroyed the second one. After Toler escaped prison, he went back to CIS headquarters to redesign the saber droid.