In Star Wars: The Rise of Skywalker, the wheel-shaped droid who joins the Resistance is named D-O.
D-O is discovered by Rey, Finn, Poe Dameron, Chewbacca, and the First Order defector Jannah on the desert world Kef Bir. The small droid has a single wheel, a tall antenna-like head, and a distinctive electronic voice. Although nervous and inexperienced, D-O becomes part of the heroes’ group during their search for the Sith wayfinder.
The film reveals that D-O once encountered Ochi of Bestoon, the assassin who had been searching for Rey’s parents. D-O’s frightened reaction to Ochi gives the Resistance an important clue about the past and about the route to Exegol.
D-O is separate from BB-8 and R2-D2, the other well-known astromech-style droids in the sequel trilogy and wider saga. The name is usually written with a hyphen as “D-O,” matching the film’s on-screen designation.