Red Dead Redemption: Undead Nightmare is an expansion pack for Red Dead Redemption on Xbox 360 that introduces a new single-player campaign. Players control John Marston as he navigates a world ravaged by a zombie plague, seeking a cure while battling the undead and encountering new challenges in the reimagined American frontier.
Red Dead Redemption: Undead Nightmare, later released as a standalone game, adds a new single-player experience in which Marston searches for a cure for an infectious zombie plague that has swept across the Old West.