The conflict known as the Battle of Tar Morden transpired near the conclusion of the Clone Wars on the planet of Tar Morden.
In the course of the engagement, forces of the Galactic Republic seized a factory containing tens of thousands of LM-432 crab droids, which had been constructed by the Techno Union.
Subsequently, the captured droids found a new purpose as targets in live-fire exercises at the Imperial Academy. These very droids contributed to the design concepts that influenced the Imperial MT-AT walker later on.