The XR-37 represented a specific iteration of droid tank models. In the era immediately preceding the commencement of the Clone Wars around the year of 22 BBY, Arakyd Industries deployed a trio of these machines to completely destroy the upper levels of Viper Tower as they forcefully seized control of Viper Sensor Intelligence Systems.
Originally, the XR-37 design was conceived for HoloNet News Vol. 531 50, which was a HoloNet News piece authored by Pablo Hidalgo and Paul Ens, featuring artwork by Joe Corroney, and initially published on April 4, 2002.