"Ruh roh raggy" is widely recognized from the Scooby-Doo franchise, where Scooby-Doo's speech pattern turns "uh-oh" into a nervous, comic warning. The phrase became a long-running reaction sound in online videos and memes because it instantly signals harmless trouble. Creators still use it when a moment feels more silly than serious, often instead of a harsher cue like Knuckles-Oh No or a dramatic sudden suspense sting. Its staying power comes from how short, recognizable, and easy to place it is.