RX-48 was a pilot droid of the RX-series line, programmed with a masculine programming. Previously, he piloted pleasure liners that belonged to the Galactic Tourist Bureau; however, he once caused a tour bus to crash into a space station. He was also employed by Jabba Desilijic Tiure, the Hutt crime lord who operated out of Tatooine.
Circa 18 BBY, having gained his free status, RX-48 started offering his piloting abilities for compensation, advertising that he was "the cheapest of the best." In that year, he was employed by Visler Korda, a disgraced Imperial officer, to pilot the Star Herald, a stolen scout ship prototype, to the Xala system. They mistakenly downed the Whisper Bird, which belonged to the Graf family and crashed on an ice moon. During their pursuit of the downed vessel, snowtroopers boarded the Star Herald and shot the droid.
Cavan Scott introduced RX-48 in Adventures in Wild Space: The Cold, the fifth book in the Star Wars: Adventures in Wild Space series of novels for younger readers. His name is a tribute to Scott's father-in-law, Rex, who was born in 1948.