What is At-at?
1.
The All Terrain Armored Transport, or AT-AT walker, is a four-legged transport and combat vehicle used by the Imperial ground forces. Standing a towering 15 meters tall, these walkers are intimidating, and are used as much for psychological effect as they are for tactical effect.
An AT-AT has blast-impervious armor plating, and resembles a gigantic beast as it moves across the battlefield. An AT-AT's head carries the main armaments, a pair of light blasters located on the walker's "temples," and heavier, twin laser cannons mounted on the walker's "chin."
The command crew pilots the AT-AT from the walker's head, which is connected to the main body by a flexible neck. The crew consists of a commander, a gunner, and a pilot. Additional crews and troops can be carried in the walker's main storage bay.
Related:
Snowspeeder AT-ST Hoth Echo Base
2.
Acronym for All Terrain Armored Transport.
AT-ATs are one of the most effective ground weapons ever created.