The phrase comes from Scooby-Doo, the long-running animated series that began in 1969 with Scooby-Doo, Where Are You, starring the cowardly Great Dane and his best friend Shaggy. Because Scooby speaks with a distinctive rhotacism, his version of uh oh, Shaggy became Ruh Roh, Raggy, a line fans quote whenever trouble appears. Clips of the catchphrase later spread through meme pages, reaction videos, and short-form edits, where its instant recognition makes it a shorthand for nervous realisation. It endures because even viewers who have never watched a full episode recognise the voice and the joke.