'Cucú cantaba la rana' is a traditional Spanish-language children's song, long taught in schools and homes across Mexico and Latin America, telling of a frog singing beneath the water. The rhyme's bouncy refrain made it a natural fit for short-form video, where it circulates as a funny, nostalgic audio for frog memes, cute animal edits and lighthearted pranks. Its charm lies in contrast: an innocent lullaby-like melody dropped over chaotic or dramatic clips.