Earlier this week, Avengers 4 directors Joe and Anthony Russo teased that the film's title should scare fans, and we at CBR suspect we know why. In order to top Thanos and the Infinity Gauntlet from Avengers: Infinity War, Avengers 4 demands a villain that would cow even the Mad Titan -- and we know just the guy: Annihilus. If Annihilus does indeed rise in Avengers 4, we can probably expect the film to be called Avengers: Annihilation.
Created by Stan Lee and Jack Kirby, Annihilus first appeared in 1968’s Fantastic Four Annual #6. The villain rules the Negative Zone, an antimatter filled parallel universe that reoccurs throughout the Fantastic Four’s adventures. Annihilus also possesses the Cosmic Control Rod, which allows him to extend his life and augment his abilities. The villain played a key role in The Annihilation Saga, a multi-title event that propelled the modern Guardians of the Galaxy to their fan-favorite status ahead of their big screen debut.
There's a good reason why Annihilus hasn't shown up in the Marvel Cinematic Universe yet, despite his importance to the Guardians mythos. According to Guardians of the Galaxy writer-director James Gunn, the rights to Annihilus have been at Fox with the Fantastic Four. Last May, Gunn revealed that he wanted to use the character, but couldn't because Marvel didn't have him: “I think that there’s a good chance that if we had all of those characters -- I really like the character of Annihilus. And there’s a chance that I would have done Annihilus as a villain in one of the movies.”
However, Marvel has already set a precedent for trading with Fox. Prior to Guardians of the Galaxy Vol. 2, Marvel and Fox reached a surprise agreement: Ego the Living Planet in exchange for permission to change Negasonic Teenage Warhead's mutant powers from telepathy to explosive abilities in Deadpool. It's possible, then, that Marvel and Fox have struck another deal for Annihilus -- or, perhaps, Annihilus was part of the earlier deal. Regardless of how Marvel may (or may) not come into possession of Annihilus' rights, we know for certain that Gunn -- who is definitely involved in Avengers: Infinity War and likely Avengers 4 -- has wanted the villain in the MCU for some time now. (Note: Although Disney acquired Fox last December, the acquisition is expected take 12 t0 18 months to complete and won't impact the MCU until after Avengers 4.)
So far as the Negative Zone goes, Marvel probably doesn't have the rights to that either, as it was introduced in a Fantastic Four comic. However, the MCU has built in a failsafe for that. Beginning with a tease in Ant-Man and later expanded on in Doctor Strange, the MCU introduced the concept of a multiverse; that is to say, an array of parallel universes. Since Agamatto, the first Sorcerer Supreme, Earth's magic wielders have defended the MCU against inter-dimensional threats like Dormammu of the Dark Dimension. They even harness mutlidimensional energy to perform what is known as magic.
To date, the MCU has established alternate dimensions like the Astral Dimension, the Mirror Dimension, the Dark Dimension and the Quantum Realm. Annihilus could easily hail from any of those instead or even from another, completely original world. In February, Doctor Strange star Benedict Cumberbatch teased that the mutliverse is about to get even bigger: “What we’ve seen happen within the Marvel Cinematic Universe is this ever-expanding coterie of superheroes, and I think now we’re at the stage where this universe, even within our world, has gotten quite crowded and it’s just about to explode into other dimensions.” As such, we know for certain that Marvel plans to explore the multiverse, and what better way to institute the dangers of such a multiverse than with a threat like Annihilus?