The sound comes from Left 4 Dead 2, Valve's co-op zombie shooter released in 2009, where Coach is one of the four playable survivors. Voiced by Chad L. Coleman, Coach is known for his loud, expressive in-game vocalisations when the team is overwhelmed or attacked. Players ripped and shared those lines on soundboards, and this scream in particular became a standalone reaction clip outside the game. It remains popular because it works without any context, instantly signalling exaggerated fear in gaming videos and meme edits.