The line comes from Super Mario 64 DS, Nintendo's 2004 remake of Super Mario 64 for the Nintendo DS, where Mario speaks short voiced phrases throughout the adventure. Charles Martinet provided Mario's voice for the era, including this goodbye heard when quitting or finishing. As clips from Nintendo games spread on video and soundboard sites in the 2010s, the buh bye was isolated as a standalone reaction sound. Its brevity and familiarity made it a lasting choice for edits referencing Nintendo and retro gaming.
About this sound
Mario saying buh bye in Super Mario 64 DS, the short voice line played when you exit a level or close the game, now used for funny goodbyes and endings.
This is Mario's cheerful goodbye voice line from Super Mario 64 DS, delivered in his high pitched Italian accented voice as a drawn out buh bye. The clip is very short and instantly recognisable, with a friendly rising and falling tone that sounds polite but also final. Players remember it from leaving courses and shutting the game, so hearing it out of context creates a playful sense of closure. Creators use that feeling to signal an exit, a fail, or a character leaving a scene for comedic effect.