The Marvel Cinematic Universe is now one of the biggest entertainment powerhouses of all time. With ten movies having been released in the franchise so far, it has grossed more than $7 billion at the global box office and is showing no signs of slowing down.
Twelve future movies are already confirmed up to 2019 - with the hotly anticipated Avengers: Age of Ultron just a couple of weeks away - including a new Spider-Man movie (though that doesn't have a release date yet), given that Marvel Studios have struck a deal with Sony Pictures to bring the flagship character into the same world as the likes of Iron Man, Hulk, Captain America and Thor.
The expanding nature of the franchise means that almost anything is possible for the future - especially given the huge back catalogue of comic books from which Marvel can pluck characters and stories. Having started off relatively grounded with Iron Man in 2008, the franchise has now reached the distant cosmos with 2014's Guardians of the Galaxy.
Even with that in mind, for various reasons some movies still seem extremely unlikely. While some of those possibilities simply won't happen, some certainly shouldn't be ruled out - and it's these implausible but possible movies that are some of the most exciting prospects.
10 The Legion Of Monsters
With the imminent arrival of Doctor Strange to the Marvel Cinematic Universe comes an entirely new set of possibilities relating to the mystical and supernatural side of Marvel.
When the franchise was first conceived, nobody in their right mind would ever have thought the Legion of Monsters would be a realistic option for a future movie, but now it definitely is.
Man-Thing - a key member of the team - has actually already been confirmed for the franchise (he was name-dropped by Maria Hill in Agents of S.H.I.E.L.D.) and the team have strong connections to Doctor Strange.
Any number of supernatural movies could now happen (a Blade or Ghost Rider reboot, anyone?), but an offering focusing on the team that also includes Manphibian, Morbius the Living Vampire, N'Kantu the Living Mummy and Werewolf by Night is definitely one of them.
With Universal's upcoming monster franchise (they're making a connected movie universe involving their classic horror creatures), Marvel Studios may want to rival them for monster superiority.
9 The Masters Of Evil
Once Phase 3 of the Marvel Cinematic Universe comes to a close, there will be a crazy number of superheroes existing in the franchise (Spider-Man, Doctor Strange, Black Panther, Captain Marvel and the Inhumans will have joined the Avengers and Guardians of the Galaxy to bulk up the heroic numbers) and individual villains just won't cut it against them.
Moreover, once Thanos with the Infinity Gauntlet (which essentially equates to God) has been defeated, any villains will be very underwhelming on their own in comparison. Therefore, a team of villains seems like a good idea and, while a villain-centric movie seems unlikely in this franchise, it's a definite possibility.
Sony Pictures will still be making their Sinister Six movie, and Marvel Studios could easily outdo them with a Masters of Evil movie. There have been plenty of characters in the Marvel Cinematic Universe to date (and there are lots on the way) who could form the team; Loki, Abomination, Red Skull, Ultron, Baron Zemo, Baron Strucker and many more could team up to rival the heroes of the franchise and that would be awesome.
8 A Female Thor Movie
Classically, Thor is obviously male - and the Marvel Cinematic Universe version of the character is no different. Chris Hemsworth has played the character since 2011, has appeared in two additional movies since then (The Avengers and Thor: The Dark World), and is set to appear in at least two more (Avengers: Age of Ultron and Thor: Ragnarok) in the next couple of years.
There has been talk, however, about the fact that he could end up being killed off. Rumours of his death in Age of Ultron have actually done the rounds (the trailers certainly point towards it), with his resurrection for a final battle in Thor: Ragnarok subsequently occurring. Ragnarok - a war of the gods - does actually entail the death of numerous key Asgardians, only for them to be resurrected in a new form. Could that new form be a female in Thor's case?
Well, Marvel has recently made the new Thor a female in the comic books - and it seems they may be testing the waters for a similar storyline in the movies. Therefore, don't rule out seeing a female Thor in the Marvel Cinematic Universe in the future.
7 The Thanos Imperative
You might think that Marvel Studios will be done with Thanos once he is defeated by the combined efforts of the Avengers and Guardians of the Galaxy in the Infinity Wars movies, but you probably shouldn't be so certain of that - for a number of reasons.
First of all, in the Infinity Gauntlet storyline in the comic books, Thanos doesn't actually die. If that's the case in the movies, there's every chance he could seek revenge in the future. Second, in the comic books, even when Thanos does die, he has a nasty habit of coming back.
Moreover, a number of the key characters from The Thanos Imperative arc are starting to appear - the Guardians of the Galaxy, Ronan and Thanos himself, while Nova is obviously on the way - so it's certainly pointing towards it.
Most importantly, however, the story sees evil alternate versions of Marvel heroes coming through "the Fault" from the Cancerverse. In Thor: The Dark World, when Erik Selvig was scrawling theories on a chalkboard in a care home, he actually wrote "the Fault", meaning that it does indeed exist in the Marvel Cinematic Universe.
Up until recently, the Siege storyline wasn't just implausible when it came to making it into a Marvel Cinematic Universe movie, it was basically impossible, but that changed when Marvel Studios agreed to a deal with Sony Pictures to bring Spider-Man and - presumably - related characters over to the franchise.
Siege followed the events of the Dark Reign arc, which saw Norman Osborn rise to national power, and had the Spider-Man foe lead a cabal of villains and manipulated heroes - most notably Sentry/The Void - into an all-out attack on Asgard (which was floating above Oklahoma - something that could be brought about by the events of the Thor: Ragnarok movie). Osborn did so due to manipulation by Loki - and everyone loves Tom Hiddleston's character, so nobody would complain about seeing him again.
Some of the characters would have to be changed (the rights to the likes of Doctor Doom are held elsewhere), but Norman Osborn is now a distinct possibility. Thinking about it, even if he is an issue (if he remains held up in Sony's Sinister Six movies) he could always be replaced with someone like Vincent D'Onofro's Kingpin. Plus, seeing Sentry/The Void in the Marvel Cinematic Universe would be nothing short of awesome.
5 Superior Spider-Man
Superior Spider-Man was a recent comic book arc that featured Doctor Octopus switching bodies with the webbed hero, allowing Peter Parker to die in his own body, then taking over as Spider-Man in a bid to reform himself from his previous villainous deeds. The problem was that Parker's consciousness was still somewhat present in his own body, causing an inner conflict to take place.
The concept was initially shunned by Spider-Man fans, but the ratings gradually improved until it actually became a very popular comic. With that in mind, if Marvel Studios wanted to differentiate their Spider-Man from those that have come in movies before it, Superior Spider-Man is certainly one direction they could consider taking it.
It might seem like an outlandish idea - that is the point of the article, after all - but it would certainly be a fresh idea and Marvel Studios must have brainstormed it to occur in at least one of the upcoming Spidey instalments (after all, it is believed there could be up to six in the pipeline).
4 Annihilation: Conquest
Ultron is set to be the main villain in the upcoming blockbuster Avengers: Age of Ultron so, given that Annihilation: Conquest also has him as the lead antagonist, it seems unlikely that it will ever see the light of day when it comes to a movie - but just think about it for a moment.
The robotic bad guy has been brilliantly cast, with James Spader in the role, and will likely be universally acclaimed for his performance. Bearing in mind what happened with Tom Hiddleston's Loki after his first appearance in Thor proved popular with fans, there's every chance he could come back.
Moreover, a cool thing about Ultron is that he can be different with each incarnation. The Avengers might destroy him physically, but his electronic consciousness might live on and he could upgrade his body for another adventure at a later date - and that's where Annihilation: Conquest might come in.
Ultron could head into space, gather the Phalanx as his army (just like in the comic book version) and face off against the Guardians of the Galaxy. It would certainly freshen him up as a concept and a new heroic set of opponents would vary things up even more.
3 Spider-Man: One More Day
Not long ago, the idea of Spider-Man in the Marvel Cinematic Universe was nothing more than a fantasy and the idea of magic in the same universe seemed too far-fetched for the then-grounded nature of the franchise. Now, it's a different story on both counts; Spider-Man is confirmed as being a part of the franchise and magic is officially on its way, with the imminent arrival of Doctor Strange.
With that in mind, there's a very distinct possibility that, somewhere along the line, Marvel Studios may just utilise the Spider-Man: One More Day storyline from the comic books.
It's a story in which Spider-Man saves his Aunt May's life by sacrificing his marriage and his life with Mary Jane Watson to Mephisto, who wipes any memory of Watson's relationship with Peter Parker from her mind.
Previous Spider-Man franchises have occurred in universes where magic was never going to appear but, now that he's in a more expansive cinematic world, it could happen - as unlikely as that may seem.
2 Planet Hulk
The potential for Hulk to pose a threat to innocent civilians has been hinted at since his solo movie in 2008. General Ross was concerned about his threat (whilst also wanting to weaponise him) and wanted to capture him. Then, in 2012's Avengers movie, Bruce Banner lost control whilst on board the S.H.I.E.L.D. Helicarrier and ended up chasing after Black Widow and fighting against Thor.
The trailers for Avengers: Age of Ultron have suggested that Hulk could pose a threat again, as he fights against Iron Man's Hulkbuster armour. Of course, it was Loki's staff that caused him to go off the rails in the first Avengers movie and it will probably be Scarlet Witch who causes him to do so in the sequel - but the fact the he is so vulnerable to being used as a pawn makes him a constant danger.
With that in mind - and even though no Planet Hulk movie has been scheduled for Phase 3 of the Marvel Cinematic Universe - the concept of the Planet Hulk comic book arc could be explored sooner than you might think.
Hulk may well be propelled into space at the end of Age of Ultron, only for the planet Hulk storyline to be intertwined with either the Guardians of the Galaxy movie or one of the Infinity Wars offerings.
1 Secret Wars
Not to be confused with the 2015 story of the same name (which would require alternative universes to exist in Marvel Studios' movie franchise), Secret Wars was a 1984 comic book story arc in which the heroes and villains of the Marvel universe were teleported to a planet called "Battleworld" by the cosmic entity known as the Beyonder.
He had created the planet himself in a distant galaxy and he used it to stage fights between the aforementioned heroes and villains for his own entertainment. He stocked the world with powerful technology and weaponry and declared "I am from beyond! Slay your enemies and all that you desire shall be yours! Nothing you dream of is impossible for me to accomplish!"
It might seem like a crazy concept for a movie, but so did Civil War until recently. And while the Beyonder is a being at a power level well beyond anything seen in the Marvel Cinematic Universe to date, it is now known that such entities do exist (the Celestials were confirmed to exist in Guardians of the Galaxy) so this storyline being turned into a movie at some point definitely shouldn't be ruled out.
Which other implausible potential movies might Marvel Studios actually produce? Let us know your thoughts in the comments section below!