The Ghosts of Halo are unidentified and/or players that tend to spawn out of nowhere during Multiplayer games, exclusively sighted in Halo 2, Halo 3, and Halo: Reach. Such ghosts tend to behave bizarrely and possess odd features. Among other things, they do not carry gamertags, do not show up on the scoreboard, and move erratically. They can be hostile if provoked, though some have been known to attack actual players for no reason. On some occasions, they are also invulnerable and will not die.