All Terrain Scout Transport/Assault

The All Terrain Scout Transport/Assault (AT-ST/A) was a variant of the AT-ST walker.

Characteristics
It was approximately 10 meters tall, and was more heavily armed than its shorter cousin (sporting a large, single-barreled heavy blaster cannon instead of the double laser cannons).

The AT-ST/A's legs had greater reinforcement, and it's gyro-stabilizing systems were improved from the original design. It was also fitted with enclosed viewports for added protection of the crew.

History
Rebel spies first spotted the vehicle early in the Galactic Civil War, but variants of the AT-ST/A design would continue to be deployed throughout the conflict, even participating in the devastating Imperial in-fighting on Coruscant in 10 ABY.

Behind the scenes
The AT-ST/As originated in concept art for the ground-battle on Endor, where it was to have taken the role of the AT-ST (which would be modified from its TESB-appearance).

Ultimately, a slightly different look was chosen and the Expanded Universe recycled the designs into a bigger, stronger AT-ST variant, more suited for an assault-role.