Fire Bros. are recurring enemy characters in the Super Mario series, including Super Mario Bros. They are Koopa Troop soldiers distinguished by their ability to throw fireballs at Mario and his allies. Usually appearing as tougher variants of Hammer Bros., they serve as mid-level or advanced obstacles that force players to time jumps carefully and avoid projectiles. Their role in the series is to challenge player movement and add variety to enemy encounters, often appearing in castle, fortress, or late-game stages.