Beefy Bert is one of Henry's classmates in Horrid Henry, the British children's books by Francesca Simon that became a long running animated television series. Bert is known for answering almost everything with I dunno, a running gag that defines his dim, easygoing personality in class and playground scenes. Clips of the line were later ripped and shared on soundboards and in fan edits, where the short delivery made it easy to reuse outside the show as a general shrug or clueless reply in memes and reaction videos.