Ay qué susto is a Spanish phrase that literally means what a scare, and it has become a familiar reaction clip in Spanish-language meme and short-video culture. The short length makes it easy to reuse, so creators drop it into pranks, horror reactions and everyday surprise moments without needing subtitles for Spanish-speaking audiences. Because the emotion is obvious from the tone alone, it also travels well beyond Spanish speakers, who recognise the startled delivery even if they do not understand every word. That instant, universal readability keeps it in rotation for reaction edits.