Possums are nocturnal marsupials known for hissing, screeching and playing dead when threatened, and short clips of those defensive calls circulate widely as animal sound effects online. Because the noise is instantly recognisable as a wild animal warning, creators reuse it far beyond nature videos, dropping it into memes, reaction edits and Halloween-style shorts for a quick burst of chaos. Its appeal is practical as well as comic: at barely over a second, it fits neatly into fast-paced edits without needing trimming, and its abrupt ending makes it easy to time to a visual gag.