The phrase literally means a rat has appeared, and online it functions as a short Spanish reaction clip rather than a line tied to a single famous show. Spanish-speaking creators use it to flag an unexpected, unpleasant discovery, and its brevity makes it easy to drop into memes, reaction videos, and chat audios. Because the meaning is clear from the tone and the word rata, even viewers who do not understand the full sentence get the joke, which has helped it circulate on soundboards and short-form video alongside other animal and surprise reaction sounds.