Players could become Thanos by equipping the Infinity Gauntlet in Fortnite. The transformation was the central mechanic of Fortnite’s 2018 Infinity Gauntlet Limited Time Mashup, a crossover with Marvel’s Avengers: Infinity War.
In the mode, the Gauntlet descended onto the Battle Royale island inside a meteor. The player who found and equipped it transformed into Thanos, gaining powerful abilities such as a devastating energy attack, a high-impact jump, and increased durability. If Thanos was eliminated, the Gauntlet dropped and another player could claim it.
The event was unusual because it placed a major film villain directly inside a standard Fortnite-style match rather than merely adding themed cosmetics. Epic and Marvel developed the collaboration quickly after discussions sparked by their mutual interest in Fortnite and the Avengers.
The answer is sometimes confused with Fortnite’s later Avengers: Endgame crossover, which used a larger team-based format and included playable heroes. The original Infinity Gauntlet event specifically centered on becoming Thanos.