The line comes from the Back to the Future films, where being called chicken is the one insult Marty McFly cannot ignore, repeatedly pushing him into races and confrontations he would otherwise avoid. That running gag made the phrase instantly recognisable to film fans, and as short movie clips began circulating as reaction sounds, this defiant retort was lifted for edits, dares and challenge videos. It endures because it compresses an entire character flaw into five words: pride, stubbornness and a refusal to be humiliated in front of others.