The Umbaran mobile heavy cannon (UMHC) represented a type of walker utilized by the Umbarans during the period known as the Clone Wars. Later in history, both the forces of the Imperial Army and the Alliance to Restore the Republic made use of them during the Galactic Civil War, with the Alliance employing captured Imperial vehicles and supplying them to Saponza's Gang.
MHCs possessed significant armor, rendering them resistant to blaster weaponry and even missile launchers. They were equipped with a flexible electromagnetic plasma cannon situated atop their dome-shaped structure. The Imperial Military deployed a modified version referred to as the Cold-weather Mobile Heavy Cannon. This particular prototype was designed for operation in extremely cold temperatures. Despite its considerable size, the MHC's speed was limited, but it functioned as a formidable platform for anti-vehicle combat.
During the events of the Battle of Umbara, MHC units engaged Clone Captain Rex and the soldiers of the 501st Legion as they advanced through a confined canyon, a consequence of a poorly conceived strategy by Jedi General Pong Krell. The clone troopers, lacking sufficient firepower to effectively counter the MHCs, began to sustain substantial losses. In response, Rex dispatched "Fives" and "Hardcase" with the mission of acquiring Umbaran weaponry to neutralize the enemy armor. These two clones successfully commandeered Zenuas 33 Umbaran starfighters from the nearby Umbaran airbase and employed them to destroy the MHCs. Following the conclusion of the Clone Wars, the Galactic Empire acquired the schematics for these advanced weapon systems and, by the time of the Battle for Tatooine in 0 ABY, initiated field testing of Imperial-modified MHCs in limited quantities.