- "General, we're picking up heavy weapons fire nearby!"
"The Rebels are attacking Tulon's units?"
"No, sir! That is most definitely not the situation here."
"What are you saying?"
"One of Tulon's walkers is attacking the rest of his units!"
- ―Anonymous subordinate and Brenn Tantor
In 3 ABY, Colonel Beri Tulon was assigned to lead an army detachment in the Massacre on Abridon. Tulon's task force consisted of one All Terrain Armored Transport, three All Terrain Scout Transports, and four stormtroopers.
Unknown to the rest of the force, Tulon intended to use the opportunity to defect to the Rebel Alliance base that he was supposed to be assaulting. Tulon turned the Annihilator 1, his personal AT-AT, on the rest of the detachment, killing them all, and fled towards the base. However, the forces of General Brenn Tantor, who was supposed to join up with Tulon for the assault, pursued him and brought his walker down before he reached the base. Tantor was shocked to discover that Tulon, his old mentor, was attempting to defect—not killed or injured at the hands of a disloyal subordinate. Tulon was seized and transferred to Tarkin Detention Facility on Ruul while Tantor completed the base's destruction alone.