Seu Madruga is the long-suffering neighbour played by Ramón Valdés in the classic Mexican sitcom El Chavo del Ocho, which became hugely popular in Brazil under the name Chaves. In the Brazilian dub, his exasperated reactions turned everyday Portuguese expressions into catchphrases, and the stretched-out nossa became a handy shorthand for disbelief. Shared widely in Brazilian meme edits, reaction videos and short clips, it still works because the character is instantly recognisable and the sound needs no translation to land.