The line comes from Doug, the talking golden retriever in Pixar's animated film Up, released in 2009, who wears a collar that translates his thoughts into speech. When Doug first meets Carl and Russell in Paradise Falls, his keen nose and eager personality quickly become part of the joke, and this short sniffing line captures that charm in just over a second. As the film became a family favourite, Doug's quotes began circulating as short soundboard clips and reaction sounds, and this one stuck because it works perfectly for spotting someone before they are seen.