Whether you believe the Marvel Cinematic Universe has maintained its greatness or feel it’s experiencing a decline, it’s undeniable that it still stands at the forefront of blockbuster filmmaking. The interconnected nature of the franchise means events in one film can (and often do) influence future projects, and part of the excitement of watching these movies is sitting in a packed theater, experiencing a surprise cameo or significant plot twist for the first time.

Consequently, leaks are a significant issue for Marvel Studios. Despite the franchise’s popularity, many fans dislike leaks because they spoil moments that could have been thrilling to discover on-screen. For example, the appearance of Sentry in “Thunderbolts*” was leaked in 2023, long before any trailer hinted at his involvement.

The saying still holds true: Don’t believe everything you read online. While numerous authentic Marvel leaks have occurred over the years, there are just as many false rumors that never had a chance of coming to fruition. Some originate from unreliable sources, while others are deliberate fabrications from Marvel Studios. Indeed, Marvel has learned to utilize leaks to inundate online discussions with misleading information. This strategy ensures that even the most informed fans might not foresee what’s coming in the next film. Here are some remarkable examples of Marvel leaks that turned out to be too good to be true.

When the Multiverse is involved, Marvel fans have come to expect copious cameos. The plot device is the perfect avenue to bring back actors who haven’t played heroes in a long time, with no strings attached, because they’re from a different reality than the main Marvel continuity. While these cameos are a fan’s dream come true, suffice it to say that Marvel would like to keep most of them a secret, even if it doesn’t always pan out that way. But even though we knew ahead of time that “Deadpool & Wolverine” would feature a variety of heroes, Marvel still managed to fool fans by planting fake rumors to throw people off the scent of who was really in the movie. 

Wendy Jacobson, an executive producer for “Deadpool & Wolverine,” explained why some of those leaked cameos didn’t come to fruition, saying, “There may or may not have been some subterfuge and misdirections on the internet or in-person in order to protect the secrecy.” For starters, rumors long persisted that a slew of former X-Men actors, like Halle Berry as Storm, James Marsden as Cyclops, and Famke Janssen as Jean Grey, would factor into the plot, and fans were absolutely convinced that Taylor Swift was poised to enter the MCU by playing Dazzler. 

It’s hard to know which rumors materialized from Marvel itself and which ones came from outlets making some educated guesses, but all of this helped hide the actual cameos we got. And we’re talking some big deals, like Wesley Snipes surprisingly reprising his role as Blade and Chris Evans popping up as Johnny Storm, but not Captain America. As for the aforementioned X-Actors, well, fans will have to wait until “Avengers: Doomsday” to see these familiar X-Men faces join the MCU.

Even Deadpool (Ryan Reynolds) admits that the MCU is at a bit of a low point right now, but Marvel Studios is betting big on “Avengers: Doomsday” turning that around. That film’s development has had its share of ups and downs, starting with it originally being titled “Avengers: The Kang Dynasty.” Changes were inevitable thanks to Kang actor Jonathan Majors’ legal troubles, issues that resulted in him getting dropped from Marvel, but Doctor Doom, played by Robert Downey Jr., feels like a suitable replacement, even if it required a title change. Ultimately, fans just want to see the Avengers together again, so many freaked out over some professional-looking, super-spoilery concept art for “Doomsday” that “leaked” online.

One piece shows off Doctor Doom’s intimidating stature, with Reed Richards (Pedro Pascal) in chains while Sue Storm (Vanessa Kirby) stands off to the side, seemingly as Doom’s wife. It even looks like Black Widow (Scarlett Johansson) is holding Reed’s chains, suggesting this is a reality where she’s still alive. Other pieces of concept art were sillier in nature, like Star-Lord (Chris Pratt) hanging out on a couch with White Vision (Paul Bettany), and Hulk (Mark Ruffalo) and She-Hulk (Tatiana Maslany) in a medieval setting, surrounded by other hulking indivduals. Fans were dismayed that the art seemed to spoil several new universes and plot points from the upcoming film.

Luckily, Marvel fans can breathe easy. The Hollywood Reporter asked the Russo Brothers, who are directing the next two “Avengers” movies, about the leak, and Joe Russo plainly stated, “That artwork was not from ‘Avengers: Doomsday’ or ‘Secret Wars.'” Anthony Russo added, “Nothing spoiling in there. That’s not our concept art.” Looks like “Avengers: Doomsday” still has its surprises intact — including which Marvel heroes may not live to see the end of it.

“WandaVision” was Marvel’s first original show on Disney+, and fans tuned in week after week to learn what the heck was going on in Westview. They also watched to see whether Marvel villain Mephisto would ever show up, as he was heavily rumored to do so. A demon ruling Hell who can manipulate reality, Mephisto’s magical abilities would’ve fit in well with Wanda Maximoff (Elizabeth Olsen) coming into her own as the Scarlet Witch. Every week, people were convinced there was more evidence Mephisto would be revealed as the show’s big bad, only for him never to show up. “WandaVision” director Matt Shakman eventually confirmed that Mephisto was never even in any drafts of the series’ scripts!

It turned out to be fake news, but why were people so convinced that Mephisto would be in “WandaVision?” Well, during the show’s run at the beginning of 2021, a toy leak of a Diamond Select Toys Minimate showed an image of Mephisto on one of the boxes. However, it was later confirmed that this toy image was a fake and wasn’t released by the company.

The conspiracies were fun while they lasted, but the true villain of “WandaVision” was Agatha Harkness (Kathryn Hahn) all along. Though this theory was thoroughly debunked, since then, MCU fans have remained vigilant, still anticipating Mephisto’s eventual MCU arrival. Basically, anytime a movie or TV show references Hell or the devil, even in passing, people are certain Mephisto isn’t too far behind.

Similar to “Deadpool & Wolverine,” fans had high expectations when it came to the variety of cameos possible in 2022’s “Doctor Strange in the Multiverse of Madness.” One of the biggest reported “leaks” was that Tom Cruise would finally enter the MCU as an Iron Man variant, with other sources saying that he could be a variant of Obadiah Stane (Jeff Bridges) from the first “Iron Man” movie. This would’ve been a fun treat for fans, particularly considering the star was in contention to play Iron Man before Robert Downey Jr. landed the gig. Cruise was too expensive pre-2008, but a fun cameo as Superior Iron Man may have been manageable for the film legend.

In the film, Doctor Strange (Benedict Cumberbatch) meets several variants during the Illuminati sequence, including Captain Carter (Hayley Atwell), Reed Richards (John Krasinski), and Professor X (Patrick Stewart) — but there’s no Iron Man, and definitely no Tom Cruise. As it turns out, the reason Cruise’s Tony Stark is a no-show is because he was never in the cards to begin with. “Multiverse of Madness” writer Michael Waldron admitted he spoke with Kevin Feige at one point about getting the “Top Gun” star as Iron Man, but it doesn’t appear like it ever went beyond that conversation, let alone filming anything with him.

That said, Cruise hasn’t closed the door on joining the MCU at some point. When speaking with Phase Zero about possibly joining a superhero project, whether it’s from Marvel or DC, Cruise said, “I don’t rule anything out. It’s, what’s the story? What’s the character? Does it interest me?” Maybe he just needs the right film to come along, something that’ll allow him to do some wild practical stunts …

Silver Surfer is one of Marvel’s most popular characters, so it’s no surprise fans have long anticipated the cosmic being joining the MCU. We’ll finally see that come to fruition when Silver Surfer (the Shalla-Bal version, played by Julia Garner) arrives in “The Fantastic Four: First Steps.” However, fans were convinced the interstellar hero would enter the fray a lot sooner with an appearance in “Avengers: Infinity War.” It’s unclear how exactly this rumor materialized, though it probably stems from the Silver Surfer having a prominent role in the “Infinity Gauntlet” comic storyline. But this rumor really shouldn’t have gained any traction because there was literally no way it could’ve happened.

As the Russo Brothers explained to Yahoo UK right before the film’s release, movie rights to the Surfer, along with other characters affiliated with the Fantastic Four, belonged to 20th Century Fox at the time. “I don’t think we [Marvel] own Silver Surfer,” Joe Russo said. “But it’s fan-wish fulfillment and, you know, if this Disney-Fox deal goes through there’s going to be a lot more characters coming into the Marvel universe, so some of those crazy fan theories might come true.” “Infinity War” came out in 2018, while the Disney-Fox merger wouldn’t be finalized until 2019. That means Marvel Studios was legally unable to put Silver Surfer in the film, even if they wanted to.

Despite that, the rumors went a step further, with some fans convinced actor Curt Clendenin was cast as the character. Years after the film’s release, he told Comic Book Movie, “I have to leave some secrecy. I don’t know how else to explain it, but time, ideally, will tell.” It’s possible he just wants to play into the hype, but maybe the Russos thought that merger would go through sooner than it did.

Fans saw just how formidable Thanos (Josh Brolin) was at the start of “Avengers: Infinity War,” when he gives Hulk the smackdown to end all smackdowns. Hulk’s so shaken up by the experience that he refuses to transform for the rest of the film, a development that some fans believed was setting the stage for Hulk to make his triumphant return in “Avengers: Endgame.”

To be fair, there was some actual physical evidence that indicated this would occur. A Funko set for “Avengers: Endgame” sold Hulk and Thanos figures together in a two-pack, so it seemed Marvel was hinting that the two would duke it out once more. Sadly, that didn’t come to pass.

But while it never materialized, it does sound like a Hulk vs. Thanos rematch was at least considered by Marvel but just couldn’t be fit into the film’s massive story. As “Endgame” co-writer Stephen McFeely told Backstory Magazine (via ComicBook.com), “I know a lot of people were saying they can’t wait for [Hulk and Thanos’] rematch. Well, that would’ve made sense had he not become Smart Hulk. He’s a whole different thing, and that’s not what drives him. So we never thought, ‘Oh, he really is trying to get a crack at Thanos now.'” “Avengers: Endgame” already has a ton going on throughout its three-hour runtime, but it does feel like a missed opportunity and something that would’ve gotten audiences cheering even more.

Since “Thor: Ragnarok” came out just a year before “Avengers: Infinity War,” many fans believed it was setting up a key plot point right in front of us. Hela (Cate Blanchett) is “Ragnarok’s” antagonist, and even though she bites the dust in the film’s climax, a rumored plot leak suggested she would fill in for Death going into “Infinity War.” In the comics, Thanos wipes out half of existence to impress the physical manifestation of Death. Despite the fact that Death, played by Aubrey Plaza, eventually joined the MCU in “Agatha All Along,” the belief among fans at the time was that it would be too weird of a concept to introduce to general audiences in a major blockbuster. Hela appeared to be an ideal stand-in as someone Thanos would want to impress.

Of course, this never panned out, though Marvel Studios president Kevin Feige played into these rumors a bit during a 2016 interview with Vulture. “Anything is possible,” he stated, “but knowledge of the comics can be both beneficial to fans anticipating things, and also misleading. So you’ll have to see.” As the head honcho overseeing everything, it makes sense Feige would dabble in these kinds of evasive statements, comments phrased in a way that ensures fans have no idea what’s going on with a project until it’s out. 

Thanos having a crush on Death is one of the many things about the character that didn’t make it into the MCU. Instead, he wants to kill half of all life in the universe so that resources won’t get depleted and lead to even more misery. Surely, the belief that Hela would stand in for Death kept many viewers off the scent of that trail prior to the film’s release. 

Leading up to the release of “Spider-Man: No Way Home” in December 2021, everyone and their mothers were convinced that Tobey Maguire and Andrew Garfield would reprise their iterations of Peter Parker for the multiversal film. No matter how much Garfield tried to deny it in the lead-up to the sequel’s release, we all knew what was going to happen, especially considering a bunch of their villains, from Willem Dafoe’s Green Goblin to Jamie Foxx’s Electro, were confirmed to return. This, logically, led many to believe that Kirsten Dunst would also reprise her role as Mary Jane Watson from Sam Raimi’s “Spider-Man” trilogy.

Even though Dunst denied any such involvement before the film came out, no one really believed her. But when the movie premiered, she really was nowhere to be found. Apparently, the reason why Dunst’s MJ isn’t in “No Way Home” is a simple one: no one asked her to join the film. It’s not for a lack of enthusiasm on Dunst’s part, as she explained to Backstage, “You know I’d join that multiverse! I feel like I’m the only one that hasn’t joined it. I’m like, ‘Please put me in. Put me in the lineup.’ I need to pay for my house and kids.” Even if the paycheck is her primary motivation, Dunst seems game for more “Spider-Man” in her life, so maybe she’ll get her chance to play MJ again before Marvel’s Multiverse Saga concludes.

Arguably, one of the strangest MCU leaks involved the announcement that Spider-Man was set to join the franchise. He first popped up in “Captain America: Civil War” before launching a new solo series starting with “Spider-Man: Homecoming.” The odd part comes in the fact that many thought that this solo outing would see Peter Parker wind up in the … Savage Land? In the comics, this is a tropical prehistoric region hidden in the Antarctic where dinosaurs roam. It’s a pretty out-there concept, especially for a movie introducing the web-spinner to the Marvel Universe. Of course, to what should’ve been the surprise of no one, Spidey remains firmly in the New York City region throughout “Homecoming.”

It’s possible this rumor grew out of a reported plot point for Drew Goddard’s “Sinister Six” movie that would’ve been a spin-off of the Andrew Garfield “Spider-Man” movies. In the book “MCU: The Reign of Marvel Studios,” there’s a quick passage about an odd detail in Goddard’s script that says, “By the end of 2014, [Goddard] had a draft that took Spider-Man and his villains to the Savage Land, where Spider-Man would ride a T-Rex.”

Plans for this “Sinister Six” movie were, of course, scrapped, and Spider-Man joined the MCU rather than having separate adventures in his own universe. Some confusion may have led fans to think aspects of that “Sinister Six” script would factor into “Homecoming,” but in the end, it was a brand new story — one that lacked any dinosaurs.