Austin Powers: International Man of Mystery introduced the character in 1997, with Mike Myers playing the time displaced British spy obsessed with 1960s style and slang. Yeah baby became one of his most quoted catchphrases across the film series and its sequels. The line moved from cinema trailers and impressions into early soundboards and later short form edits, where its short length made it easy to reuse. It remains popular because the reference is widely recognised and the meaning is clear even out of context.