Remember Ultron? The AI Frankenstein's monster birthed by Tony Stark (Robert Downey Jr.) and Bruce Banner (Mark Ruffalo) was the frighteningly powerful nemesis of the Marvel Cinematic Universe's second Avengers movie, but once his primary body was eliminated by Vision (in a surprisingly moving scene), he ceased to be a factor in the superhero franchise. 10 years after the release of "Avengers: Age of Ultron," the character has been completely Mia in the movies and TV spinoffs. Yes, he's due to return in next year's Disney+ series "Vision Quest," but that's an awfully long time to put a fascinating, once-titular villain on ice.

Though it's not officially canon, Ultron has actually been a tangential part of the studio's muddled Multiverse saga for nearly three years now. And if you've spent a few days aboard the Disney Wish cruise ship, you've almost certainly gotten reacquainted with the AI baddie via the dinner theater-esque "Avengers: Quantum Encounter.