What If, sometimes stylized as What If…?, is a comic book anthology series published by Marvel Comics whose stories explore how the Marvel Universe might have unfolded if key moments in its history had not occurred as they did in mainstream continuity. Since What If debuted in 1977, the comics have been published in 14 series as well as occasional stand-alone issues. In 2024, Marvel announced that What If…? would expand to include alternate explorations of continuity within other non-Marvel Universe properties owned by their parent company The Walt Disney Company from its fifteenth volume onwards, beginning with Aliens: What If…?, based on the Alien franchise.

James Buchanan "Bucky" Barnes is a character appearing in American comic books published by Marvel Comics. Originally introduced as a sidekick to Captain America, the character was created by Joe Simon and Jack Kirby and first appeared in Captain America Comics #1. Barnes' original costume and the Bucky nickname has been used by other heroes in the Marvel Universe over the years.