The whistle comes from Puss in Boots The Last Wish, released in 2022, where Death is portrayed as a white eyed wolf who hunts Puss throughout the film. His whistling announces his presence before he speaks, so audiences learned to associate the tune with him being just out of sight. Clips of the scene spread widely on TikTok and YouTube in early 2023, and editors began lifting the audio alone to place over other characters, pets and people walking into frame. Its clarity and instant recognition have kept it in use as shorthand for looming danger.