The All Terrain Anti-Aircraft (AT-AA), a heavily armored walker, was developed by Rothana Heavy Engineering during the Clone Wars’ final year. It belonged to their AT-series walker line and was used by the Galactic Empire’s ground forces for anti-air defense.
This durable walker, known as the All Terrain Anti-Aircraft, remained in service with the Imperial Army as a mobile, heavy anti-aircraft platform. Its design was unusual; it was built long and close to the ground. Unlike the taller All Terrain Armored Transport or All Terrain Scout Transport, it had four short legs extending from the sides of its hull, giving it a lizard-like movement and appearance rather than a mammal-like one. A crew of three – a pilot, a gunner, and a commander – operated the walker from a cramped control pod at the front. The rest of the vehicle housed its power, drive, and fire-control systems.
The AT-AA, which was heavily armored for a walker of its size, was a slow-moving vehicle more suited to rear-echelon support like over-the-horizon artillery and air defense instead of frontline combat. It was armed with either a turret-mounted twin light flak cannon or a turret-mounted concussion missile launcher. This armament, combined with its advanced air-defense targeting system, allowed squads of AT-AAs to effectively control large areas of airspace, preventing enemy airspeeders and starships from entering. Although they could hold off entire squadrons with flak bursts and concussion missiles, the lack of secondary weapons made them very vulnerable to ground attacks. Despite having firing ports for the crew's personal weapons, the AT-AA had limited defenses against determined ground-based enemies, so it was often deployed with infantry and AT-ST support.
Production of the All Terrain Anti-Aircraft began during the Clone Wars’ final year. Later, during the Imperial Era, the Galactic Empire used these walkers within its Army. On one occasion, a walker was seen with scout troopers riding All Terrain Reconnaissance Transports.
The All Terrain Anti-Aircraft became part of the new Star Wars canon through its inclusion in Fantasy Flight Games' 2020 Star Wars: The Roleplaying Game supplement, Starships and Speeders.