Number Four was an All Terrain Armored Transport used by the Imperial Army of the Galactic Empire. It was later used by Grand Admiral Thrawn against the smuggler Talon Karrde's base on the planet Myrkr. It was under command of an unnamed officer, and ultimately, General Covell. It worked alongside other AT-ATs, including the Number Two, as well as repulsorlift tanks and All Terrain Scout Transports.