What is ruh roh?

"Ruh roh" is a catchphrase made famous by the cartoon character Scooby-Doo. It is an expression of surprise or alarm and is often used when something unexpected happens. The phrase is most commonly associated with Scooby-Doo's character and is often used to indicate that he has encountered a problem or danger. The phrase has become popular outside of the world of cartoons and is now commonly used in everyday language to indicate surprise or concern.