Ultra Instinct Shaggy is a legendary meme that reimagines the cowardly Shaggy Rogers as an omnipotent deity capable of reality-warping feats. The trend began in 2017 when a YouTube user uploaded a clip from the film 'Scooby-Doo! Legend of the Phantosaur' where Shaggy takes on a biker gang, set to the theme 'Ultimate Battle' from Dragon Ball Super. This birthed an entire lore where Shaggy only uses a tiny fraction of his power to defeat cosmic threats like Thanos or Madara Uchiha. It has since become a staple of internet culture, often used to showcase unexpected dominance or to mock traditional power scaling in anime and movies.