Roadrunner is a Duel Runner-themed character and monster associated with Yu-Gi-Oh! 5D's, best known as a supporting card used by Yusei Fudo. It appears as a fast, bird-like machine monster that helps emphasize Yusei’s Speed Duel style and the series’ focus on momentum and racing. Rather than being a major independent character in the story, Roadrunner functions as a recurring utility monster and symbolic companion, representing agility, speed, and adaptability in duels.