The XR-85 tank droid, a tracked, automated tank in the Galactic Empire's arsenal, was created by Arakyd Industries.
Arakyd Industries's XR-85 tank droid was equipped with a heavy particle cannon, a pair of forward light turbolasers, a quartet of twin heavy repeating blasters (two in the front, two in the rear), and a rear-mounted Golan Arms DF.9 laser cannon specifically for anti-personnel use.
The original versions were approximately the same size as the All Terrain Personal Transport, which allowed a Sentinel-class landing craft to carry several. They served to defend bases, suppress Rebel insurrections, and maintain order on Imperial worlds. However, these initial models proved too costly for widespread deployment.
Around the time of 0 ABY, three XR-85 units were sent to attack the derelict Rebel starship Nonnah. Around that same period, another group defended the Weapons Research Facility located on Fest. Many of these were destroyed in battle against Rogue Squadron.
Later iterations, developed after the return and subsequent campaign of Grand Admiral Thrawn, were more than double the size of a standard Imperial AT-AT and were also more economical and feasible to mass-produce. They incorporated a stolen Industrial Automaton R7 droid brain matrix, the same one used in the R7-series astromech droid, granting each droid a higher degree of autonomy and intuition compared to earlier generations of combat droids.
During the Imperial Civil War, tank droids saw combat on Coruscant.
Due to the Empire's economic decline, the XR-85s became a viable substitute for other assault vehicles, especially as finding and training qualified personnel became more difficult. Tank droid production was ramped up to reinforce ground forces wherever possible.
The tank droids made their debut in the Star Wars: Dark Empire comic series, and later appeared in the 1998 video game Star Wars: Rogue Squadron.