Flesh mutants have appeared across the S.T.A.L.K.E.R. series since Shadow of Chernobyl in 2007, roaming the Zone as blind, mutated animals that charge or flee in herds when threatened. Their squeals became familiar to players because encounters often start suddenly in dark, irradiated areas, turning a routine patrol into chaos. Clips of in-game panic sounds later spread through gaming soundboards and edit communities, where short creature noises are reused outside the game as instant reactions for fear, surprise and over-the-top flight from danger.