He's a Bully, Charlie Brown(2006)

He's a Bully, Charlie Brown is an animated film following Charlie Brown as he and his friends attend summer camp. There they encounter Joe Agate, a cunning bully who tricks children into playing marbles for keeps, stealing their prized collections. When Rerun falls victim to the scheme, Charlie Brown decides to challenge Joe at his own game to recover the stolen marbles. The catch: Charlie Brown has no idea how to play. What unfolds is a heartfelt story about standing up to bullies and the courage it takes to face someone stronger, even when the odds are stacked against you.