The sound comes from Canal do Otário, where the phrase 'que legal' is delivered as an enthusiastic reaction to something impressive or enjoyable. Shared as a short standalone clip, it travelled beyond its original videos into memes, edits and reaction content, especially among Portuguese-speaking creators and audiences who recognise the expression instantly. Its appeal is its clarity: no setup is needed to understand the approval it expresses. That makes it a handy shorthand for delight, and it continues to appear whenever a creator wants a warm, human reaction rather than a loud sound effect.