Both Paul Bettany and Elizabeth Olsen have teased a big guest star in WandaVision, and while it's possible we already met the actor the former says he's been desperate to work with for years last week, the signs are pointing to some sort of surprise in the finale.
There are some obvious possibilities - Doctor Strange, for example - but we have some wilder suggestions for who could make an appearance.
From a resurrected hero to characters from other worlds, there are some exciting possibilities here, all of whom could prove to be a game-changer for the Marvel Cinematic Universe moving forward.
WandaVision has already delivered some huge surprises, and it would be foolish to think there aren't more to come. We don't know if this major cameo will take place, of course, but Marvel Studios is using this series to set the stage for Doctor Strange in the Multiverse of Madness, remember!
We think you'll have some fun with this one, so click on the "Next" button below to take a look...
5. The Original Quicksilver
At the end of last week's episode of WandaVision, we learned that Wanda (or someone...) had "recast" Pietro. Playing Wanda's long-lost brother was Evan Peters, the actor best known for starring as Quicksilver in Fox's X-Men movies. Look online, and you'll find plenty of theories about him.
Some believe it's Pietro's "spirit" in a new body, while others have argued this is just a random Westview resident forced to play Wanda's brother. The most compelling theory, however, is that he's secretly Mephisto, and is only there to manipulate the Scarlet Witch and stop her leaving this reality.
Regardless, we honestly wouldn't be surprised if Aaron Taylor-Johnson makes his surprise return as the real Quicksilver. If Wanda fully embraces her reality altering powers in the finale, then she could bring the real deal back from the dead, proving that there are no limits to her powers (and, despite what she told Billy and Tommy, the Scarlet Witch is powerful enough to break the rules).
4. Mojo
Even assuming Mephisto isn't responsible for what's happening in Westview, it's still safe to assume that "Agnes" will be revealed as Nightmare (likely combined with Agatha Harkness).
The ruler of the Dream Dimension clearly wants to get her hands on the twins for some sort of sinister reason, but what's the deal with the sitcoms? Well, that could be explained with the introduction of Mojo. His race was driven insane by television signals from Earth, and he loves creating his own entertainment...so, what if Nightmare was forced to turn to him for help here?
She might not be powerful enough to trap Wanda in a setting where she can be easily manipulated, hence why Mojo was necessary to create a sitcom world, and provide the necessary technology. This would be a weird direction to take things down, but Marvel Studios might be able to pull it off!
If nothing else, he might be shown tuning in...
3. Spider-Man (Not That Spider-Man)
Despite what Tom Holland says, the signs do appear to be pointing to Tobey Maguire and Andrew Garfield being part of Spider-Man 3. Plus, with Sam Raimi at the helm of Doctor Strange in the Multiverse of Madness, the prevailing theory is that the Sorcerer Supreme will team up with Maguire's Spidey.
Don't forget, Sony Pictures has agreed to allow Marvel Studios to use Spider-Man in at least one more MCU movie, but who said it had to be the version played by Holland?
So, if the Scarlet Witch is responsible for tearing a hole in the Multiverse, it's feasible we'll get our first look at Maguire's world, and Strange will need to enlist his Spider-Man's help to get this one back to his world. Perhaps this will take too much time, but if nothing else, a glimpse to tease Spider-Man 3 would work!
2. The Beyonder
If it's not Mephisto pulling the strings, then there's another possibility (and one who could be used to lay the groundwork for Phase 4/Phase 5's new big bad). Just like Thanos was introduced in The Avengers' post-credits scene, The Beyonder could appear in WandaVision's stinger.
Revealing he was responsible for twisting reality and creating those sitcoms, the stage would be set for an even bigger clash down the line...Secret Wars! Avengers: Endgame directors Joe and Anthony Russo are keen to make that a reality (no pun intended), and a being as powerful as The Beyonder could explain both the Multiverse madness and the introduction of the X-Men.
A slow-burn approach to this debut would be sensible, but some sort of tease in the WandaVision finale - with an A-Lister playing the villain - would be nothing short of mind-blowing for comic book fans.
1. Magneto
How cool would this be?
There was a fake leak about Magneto appearing in WandaVision, but the iconic comic book character arriving to claim his daughter (similar to the end of Avengers Disassembled) would be one heckuva twist, teasing a secret origin story for Wanda Maximoff and the arrival of mutants.
If they've been hiding out in the shadows all this time, then it makes perfect sense for Magneto to make his presence felt, taking his mutant daughter back to Krakoa or wherever the mutants call home.
We'd lose our minds if Michael Fassbender plays Erik, and that could tie nicely into whatever is going on with the Multiverse (similar to Evan Peters returning as Quicksilver). Time will tell, but it would be a big mistake not to explore Wanda's history as a mutant and with her father, Magneto.