Pato is the Spanish and Portuguese word for duck, and quen quen is a playful written form of its quack, which is why this short clip is shared mainly as a light animal meme sound. It has no clear single source scene or famous character attached to it, so its appeal comes from the sound itself rather than a film or television moment. Online creators use it as a quick animal reaction, a cute interruption or a way to label someone as a duck in a joke, and its two-beat rhythm makes it easy to remember after hearing it once.