The line comes from Scooby-Doo, the long-running cartoon about Shaggy, Scooby and their friends solving mysteries, where Shaggy often warns Scooby that trouble is coming. His slurred, nervous delivery turned Ruh-roh, Raggy into a recognisable catchphrase that fans repeat and remix. On TikTok and in short edits, creators reuse the short audio as a punchline for impending disaster, keeping it alive long after the original episodes because the panic is instantly understood even without seeing the cartoon.