Captain America: New World Order will combine some of the very newest and oldest elements of the MCU. At today's D23 Expo, Marvel Studios revealed one of the villains we can look forward to seeing in the movie: The Leader.

If you don't remember Leader, that's okay, because he was only hinted at in his last appearance, and that was almost 15 years ago at the very end of 2008's The Incredible Hulk, the second MCU movie. The movie starred Ed Norton as Bruce Banner, years before the character was recast with Mark Ruffalo in the role. Tim Blake Nelson appeared as Samuel Stearns, and we saw in the movie's final moments the beginnings of his transformation.

While gamma radiation turned Bruce Banner and his cousin Jen Walters into some of the very strongest beings on the planet Earth, Stearns became one of the most intelligent, with his head growing instead of his muscles. The Leader is one of the Hulk's most frequent enemies, though there's no indication yet that Banner himself will appear in the fourth Captain America film.