Annihilus is one of the biggest villains in the Marvel Universe. He's gone toe to toe with the Avengers, the Fantastic Four and the Guardians of the Galaxy. Almost the entire universe had to unite and go to war with him to stop his assault in the crossover event, Annihilation. In short, he's kind of a big deal.

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So it's no surprise that fans are expecting the character to play a role in the Marvel Cinematic Universe. But many fans expect the character to even appear within Avengers: Endgame, as the mysterious threat that could supersede even Thanos. Despite fan theories and even potential references to the character, it doesn't seem likely at all for the character to appear in the film... or does it?

Who Is Annihilus?

Created by Stan Lee and Jack Kirby in the pages of Fantastic Four Annual #6, Annihilus was introduced as the ruler of the alternate universe known as Negative Zone. He ran afoul of three quarters of the Fantastic Four when the group came to the Negative Zone looking for a particular isotope that could be used to save Sue Storm and her unborn second child. The insectoid figure spent decades primarily as a threat to the Fantastic Four, although he did play occasional roles in stories like The Kree/Skrull War. He was so defined by his connection to the Fantastic Four that the MCU technically couldn't use him in a film until they got the rights for that entire corner of the Marvel Universe.

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His recognition within the main Marvel Universe jumped up considerably during the events of 2005's Annihilation. Revealed to be leading a veritable army of ships and warlords from the Negative Zone into the core Marvel Universe, it took the entire cosmic side of Marvel to fight him back. The event led to the resurgence of the Guardians of the Galaxy, and helped propel them into the spotlight enough that the MCU even brought the team of universal misfits into the film universe. However, there was no sign of Annihilus in either of the two Guardians films, despite the treasure trove of easter eggs hidden in both movies.

What Fans Expect

That hasn't stopped fans from looking for hints of his arrival. Before the revelation of Endgame being the official title of the next Avengers film, a number of fans put their faith in the film being named Annihilation. Hints from the packaging of toys set to be released for the film teased that an even greater threat than Thanos is set to appear in the film, leaving many fans to assume this would be the introduction of the character. Some theories suggest that he could even appear within the Quantum Realm, which could be an equivalent to the Negative Zone and could serve an introduction to the character.

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The latest potential clue has been the tie-in website for Captain Marvel. The website is a retro inspired page, visually reminiscent of clunky websites from that era. The thing is, the URL shortener used by Marvel to promote its 1990s-flavor website could be taken as a sly reference to the character: https://i.annihil.us. All of this plays into the consistent and persistent rumors and theories about the character playing a role in Avengers: Endgame. Unfortunately, though, the facts just don't add up.

Why It's Not Going To Happen

The title is clearly not going to be Annihilation, as it's been confirmed as Endgame. The Celestials have been introduced in the MCU, and with their connection to the Infinity Stones, would be a far likely threat to serve as the overwhelming enemy to appear in the film than any appearance of Annihilus. And the most recent clue? The Annihil.us domain for the Captain Marvel website isn't just used for Captain Marvel. It's actually a clever URL short-hand that is commonly used by Marvel for multiple projects and websites.

Even with Disney acquiring the full rights to the character by purchasing the 20th Century Fox assets, the move was made well after Endgame had been plotted out and written. That deal was only finalized months ago, well into the production of EndgameThe film will be released just after the deal officially goes through. And remember, it wasn't always clear that it even would actually go through. There's no way the filmmakers would have risked losing such an important of the movie based on decisions out of their hands, so they probably didn't include him.

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But why do so many MCU fans believe Annihilus will appear in the film? Part of it is probably because Annihilus is just a really cool villain. Alongside Doctor Doom, he's one of the most intimidating villains who previously couldn't appear in the MCU, even though he has a history of fighting the entire universe. The tease that another villain even worse than Thanos will appear in the film means it would have to be someone comparable to the scale of Annihilus.

Another possible factor is that for the first time since Phase 3 was publicly introduced, fans have no idea what's coming for the future of the MCU. The universe could look radically different, and it's left fans looking for any hint they can find about what comes next. Annihilus could show up in the MCU someday -- he's a dynamic enough villain that he could even replace Thanos as the overarching villain of the entire universe going forward -- but expecting him to make an appearance in Endgame is a long shot, no matter how many "clues" fans think they've found.

Directed by Joe and Anthony Russo, Avengers: Endgame stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Chadwick Boseman, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland, Gwyneth Paltrow and Anthony Mackie. The film arrives Apr. 26.