R5-D4, also called «Red» by Luke Skywalker, was a red and white-striped R5 astromech droid owned by a group of Jawas on Tatooine in the early days of the Galactic Civil War. Shortly before the Battle of Yavin, the Jawas attempted to sell him to Owen Lars, but the droid purposely malfunctioned his motivator at the advice of R2-D2, so that Lars could purchase R2-D2 in R5-D4’s place. The droid survived an Imperial attack on the sandcrawler soon after, and went out to find the Rebellion. R5 was still active by the time of the New Republic Era, and eventually came into the service of Mos Eisley hangar manager Peli Motto. He projected a map of Tatooine in order to assist the Mandalorian Din Djarin.
Did you know that R5-D4 caused a lot of problems on the set of Star Wars? The droid’s head was of course meant to explode, but it was constructed with all of its remote controls inside its head. So they couldn’t have it both roll and explode. So they rushed to repaint another droid read, put the exploding head on the replacement, and simply used piano wire to drag it along the sand.