Left 4 Dead is Valve's cooperative zombie shooter, released in 2008, and its infected snarls, alarms and gunfire became some of gaming's most recognisable audio. Short clips like this one spread through meme soundboards and gaming montages, where editors needed a split-second scare or punchline without a long build-up. Because nobody can pin a two-tenths-of-a-second clip to a single famous moment, it survives as a generic horror scream meme staple rather than a quoted line. It still shows up whenever a creator wants instant zombie-game energy.