Arnold was a student at Rydell High School during the 1958-59 school year. Who he was played by is unknown.
Roll in film
Arnold is only present during the scene when Danny tries out for the basketball team. Arnold is shown to be on the team, and a skilled player. After he steals the ball from Danny, and takes it back to the court with another guy guarding him, his name is revealed when another player says, "Come on, Arnold." Arnold takes his shot and it goes it. Artie yells, "Get him, Danny," when another player passes the ball back to Arnold, and Danny goes up to guard him with his arms up. Arnold tries to pass around Danny, but no one is close enough. Soon enough, with a clear view, Danny punches Arnold right in the stomach and exclaims, "What'd I do?" when he hears Coach Calhoun blow the whistle. Arnold isn't seen or mentioned for the remainder of the movie. It's unknown if Arnold was still going to Rydell in 1961-62, or if he'd graduated between movies, or transferred.