The cuak sound is widely used across Spanish-speaking meme pages, short video edits, and WhatsApp forwards as a tiny audio punchline. Rather than pointing to one clearly documented source, its popularity comes from how flexible it is: one syllable, immediate timing, and a goofy tone that reads as irony. It spread as a reaction sound for anticlimactic moments, similar to how creators use a buzzer or bruh-style button to underline embarrassment, failed jokes, or silent reactions.