9 Times Rogue One References the Other Star Wars Movies

Short for All Terrain Armored Transport, these walking armored vehicles are infamously used by the ground forces of the Galactic Empire. They first appear in The Empire Strikes Back during the Battle of Hoth, and come in varying forms such as the two-legged AT-ST (All Terrain Scout Transport) in Return of the Jedi and the AT-OT (All Terrain Open Transport) as seen in Revenge of the Sith. In Rogue One, we see AT-ACT (All Terrain Armoured Cargo Transport) walkers wreaking havoc on the rebels during the final battle.