The hiss comes from Minecraft, where cats and ocelots use the sound as a defensive warning and creepers instinctively avoid them. Players hear it during close encounters around villages and homes, so the clip is instantly recognisable to anyone who has played the game. As short form gaming edits grew, creators lifted the clean one second hiss for use outside the game as a reaction sound. Its popularity comes from that clarity, a real animal warning compressed into a game cue that needs no context to understand.