The sound comes from the Zombies mode in Call of Duty, first introduced in World at War, where a teddy bear appears when the mystery box moves to a new location on the map. Players quickly learned to dread that innocent-looking bear because it meant losing a useful weapon spot and hearing its strange music-box tune. Clips of the moment spread through gameplay videos and streaming, and the jingle became shorthand for creepy, unexpected change in gaming memes and horror edits, which is why creators still use it long after the original maps.