The phrase comes from Surfin Bird, the 1963 hit by The Trashmen that combined two Rivingtons doo wop songs. It returned to mainstream attention in the 2008 Family Guy episode I Dream of Jesus, where Peter Griffin becomes obsessed with the record, sings it constantly, and drives his family insane. The episode helped push the song back into the charts and turned Peter's version into a widely shared meme clip, quoted and remixed online long after the episode first aired.
About this sound
Peter Griffin repeatedly singing bird is the word from Family Guy, taken from his obsession with Surfin Bird, used for annoying repetitive joke reactions.
This clip captures Peter Griffin launching into his manic rendition of the chorus from Surfin Bird, repeating the line that the bird is the word over and over with growing enthusiasm. His loud, nasal delivery is deliberately grating and impossible to ignore, delivered in a rapid sing-song rhythm that quickly takes over the scene. The joke comes from the repetition itself, as other characters grow tired while Peter remains completely delighted. As a standalone sound it works as an instant earworm, bringing that same obnoxious, energetic persistence into any conversation or edit where it appears.