The grunt comes from Super Mario 64, released for the Nintendo 64 in 1996, where Mario makes short exertion sounds while running, jumping and bumping into objects. As the game became a staple of retro gaming culture, its individual voice clips were ripped and shared on soundboards, and this tiny 'ungh' stood out because it was so brief and easy to drop into edits. It spread through gaming montages and meme videos, where creators use it as a shorthand reaction for a small mistake, and it remains popular because almost anyone recognises Mario's voice instantly.