The 'The Ass Was Fat' meme, also known as 'Arthur Sees A Fat Ass,' originated from a 2010 parody edit of the children’s show Arthur. The image features Arthur wearing glasses, staring in wide-eyed shock or appreciation at an edited version of the character Francine. While the original edit was a piece of shock humor on 4chan, the phrase and Arthur's reaction quickly evolved into a universal internet shorthand for expressing disbelief or a humorous fixation on something surprisingly large. Today, it is a staple of reaction image culture, frequently used to comment on unexpected visual details in movies, games, and viral photos.