The line comes from You're a Mean One, Mr Grinch, the song written for the 1966 animated television special How the Grinch Stole Christmas, based on Dr Seuss's story. Sung in the special by Thurl Ravenscroft, it lists the Grinch's faults in a series of witty insults set to a jaunty, mocking tune. The song became a Christmas staple through annual broadcasts and later film versions, and short clips of its opening line now circulate widely in holiday memes, TikTok edits and reaction videos, where it instantly signals that someone is being called out.