Just a couple of years ago, who would have thought that a studio would bet on an R-rated Deadpool movie? And who would have thought that the bet would pay off, big time?

We guess that not even the most hardcore Deadpool fans expected the big returns at the box office, nor the praise from the critics. But it happened - so, what’s next? In addition to the R-rated superhero flick trend that people say Deadpool started, the movie will get a sequel, most likely in 2018. And another fan-favorite mutant will make his debut in the sequel: Cable, the no-nonsense mutant with whom the Merc with a Mouth makes such a lovely pair.

But what other characters should there be in the second Deadpool? Well, we have some pretty interesting ideas, for both villains and allies. So check this list out!

Ajax

Let's get this out of the way - as Ed Skrein has said, his version of Ajax was just an early version of the villain (an early and cost-effective one, that is). And, as we all saw, Ajax actually died at the end of Deadpool. But did he really?

In the comics, the two have battled it out a couple of times; on one occasion, Deadpool seemingly killed his enemy. But, as it was later revealed, Francis survived, and came back with a vengeance. And this time, he wasn't just using his super strength, increased agility, and accelerated healing. He also received some implants to make him even more dangerous.

How dangerous? To put it simply, he managed to defeat the Merc with a Mouth several times, before having his neck snapped.

So yes, Ajax would be great for a second outing. Furthermore, he might have a personality this time around.

Copycat

Another character who appeared in the first movie – and who should appear in the sequel – is the lovely Vanessa, Deadpool's girlfriend. And she should appear not just for continuity's sake; she should also develop some extraordinary abilities.

In the comics, she’s an extremely powerful shapeshifter known as Copycat, who can mimic anybody just by knowing details about their lives. Her superpowers are so extreme that, when Weapon X tampered with her abilities, she lost the ability to maintain a solid form.

Now this could be the motor of the second Deadpool movie. As we saw this year, Ajax actually had her in a tank, and was experimenting on her. So, what if he triggered these abilities into her body? And what if Deadpool's girl finds out that she can’t control these powers?

The Merc with a Mouth would once again have to search for a cure, this time for her. And who knows who he would find behind the entire program?

Mister Sinister

Mister Sinister is one of those villains who is long overdue. A human who became a mutate after encountering Apocalypse, Sinister is one of those supervillains who can appear all over the place in the X-Men universe. Because of his shape-shifting abilities, we wouldn't even know he was there.

He has quite a few extraordinary powers, including telepathy, complete control over his body, an accelerated healing factor, and telekinesis. But, above all, he is a super-scientist, a sort of modern Frankenstein who tries to create the perfect being.

So he could be behind the Weapon X program, and he could be the perfect villain for Deadpool. As we know after seeing this year's hit, the Merc with a Mouth has seemingly ended his career as a sort of superhero. With Vanessa in trouble, he could go on another mission, to discover who is behind his and his girlfriend's new condition.

Knowing that Apocalypse arrives this year, knowing that next year Gambit might introduce Sinister, and knowing that Bryan Cranston teased this particular character"¦well, you can do the math.

T-Ray

When you have an extraordinary character such as Deadpool becoming a hit on the big screen, can you take it a bit further and make a sequel that’s even more mind-bending? We guess the studio can. And the perfect way to do that is by introducing T-Ray, who is basically a zombie filled with dirt.

A voodoo expert with superhuman strength, this character seems so appealing to us because of his special relationship with Wade Wilson. And this relationship is so special that T-Ray actually believes that he is Wade Wilson, who had his personality stolen by Jack, who tried to escape the Weapon X program.

Yes, it is mind-bending. But this would be yet another cheap character the studio could use. Instead of having the Merc with a Mouth going on a vengeful quest, have the villain do it, instead. Imagine how awesome and twisted their encounters would be.

Basically, to a certain degree, it would be as if the sequel featured two Deadpools"¦

Yes. We cannot get enough. Speaking of which"¦

Evil Deadpool

Sure, Fox can use T-Ray. But why not go the extra mile and literally have two Deadpools? As we saw this year, when escaping Colossus, the Merc with a Mouth cut one of his hands off. What happened to that hand?

In the comics, Evil Deadpool (called Dreadpool) is accidently created by Deadpool himself, who throws several of his own body parts (which he found at some weird scientist’s lair) into the dumpster. Miraculously, the body parts unite one with another and regenerate, creating a being who has no conscience. Lacking a mind of his own, Dreadpool knows just one thing: he has to kill everyone.

As we saw this year, Deadpool can regenerate body parts. But what if some writer finds the perfect formula for the big screen, and says that the body parts can regenerate the Deadpool? Here is the perfect origin story for Dreadpool - he will actually need to kill everybody, especially since he is created from the hand used by Wade for"¦well"¦touching himself.

If you knew you spawned from the hand that beat the monkey, you would too want to kill everybody in your path, too!

Bob, agent of nothing

Who is Bob?!? Well, he’s basically a parody of all evil henchmen, those guys who rarely hit the target, and are just nuisances in the face of a true superhero. Bob appeared this year in Deadpool as one of Ajax's henchmen. And he didn't die! The Merc with a Mouth spared him, even if he knocked him unconscious.

So what if he appears again in the sequel? He was Bob, the agent of Weapon X in the first one. He could be Bob, the agent of nothing, in the second one. And even if it would just be a cameo, it would still be awesome. It could become some sort of recurring joke throughout any and all future Deadpool films.

Yeah, it won't bring anything to the movie - but it would surely be fun to see Wade Wilson recognize him all over the place. After all, Deadpool did say in the comics, that Bob is the best at running away (at one time, the character even killed a symbiote possessed dinosaur while running away).

Domino

If this year we were introduced to Negasonic Teenage Warhead as an X-Men trainee, maybe the Deadpool sequel should introduce another one. And what better character could there be than Domino? Once again, we should mention that she is quite cheap for the studio, given her powers and abilities.

Basically, Domino subconsciously influences her luck by subconsciously initiating telekinetic acts. In a way, for as long as she is on the move, all the best and most improbable things will happen to her.

The rumor is, at this point, that the planned X-Force movie will also feature Domino. But there is another reason why the Deadpool sequel should feature Domino - she has a special relationship with Cable, as his partner, confidante, and lover.

We're not even going to mention how awesome she looks in her outfit. No matter what villain will appear in the sequel, having Domino is a must!

Taskmaster

When you have one of the most unpredictable characters as your hero, what better villain could you find than Taskmaster? He would be perfect to fight Deadpool!

As it is known, Taskmaster was supposed to appear this year as the main baddie. But, due to his rather expensive persona, the studio opted for a dumbed down Ajax. Seeing how successful Deadpool is (ten times its original budget, and counting), maybe the powers that be will pit the Merc with a Mouth against the villain who can replicate anybody's physical movements.

And that is because this is Taskmaster - someone who has the ability to replicate even the most intricate movements, and who can thus predict what the enemy will do. It would be up to Deadpool to find a way around this and defeat him.

Because, let's be honest, Wade's maniacal persona wasn't explored to its full potential this year. Maybe in 2018, when the sequel is supposed to arrive, he will have a reason to go completely bonkers. And then enters the Taskmaster!

Squirrel Girl

It’s more than obvious that a Deadpool sequel can introduce characters we wouldn't otherwise see on the big screen. Squirrel Girl is one of those characters - basically, she is a humanoid-sized and shaped squirrel, who can communicate with…well, squirrels.

But she is interesting, since she has defeated some of the biggest and worst of the marvel comic book universe, including in here the likes of Doctor Doom, MODOK, and even Thanos. Yes, the fights occur off-panel, but still"¦

Interestingly enough, she did have some encounters with Deadpool. When they fought, she defeated him - when they were allies, she kicked him off the team. At any rate, she could be among the characters to see.

For that matter, she could also be one of the X-Men trainees, popping in the movie, just like Negasonic Teenage Warhead did.

Polverine

We know - Hugh Jackman will be done with Wolverine after 2017. But he did say that he’d be open to doing a Deadpool cameo. And since both he and his character were teased this year, what if"¦?

And it shouldn't be too big a role for Hugh Jackman. We could even settle for a cameo similar to the one in First Class. Obviously, it would be awesome if the two fought on screen. But the best chances are that this wouldn’t happen.

Yes, we are disregarding X-Men Origins: Wolverine, just like everyone else.

Have him pop on screen for a couple of seconds, express his opinion about the Merc with a Mouth, have Wade crack some jokes, and be done with it!

Six Pack

Deadpool 2 will feature Cable. And, when that happens, maybe we will receive some information about the newly introduced character. Most notably, besides being an X-Force member, Cable is also known for being a member of the Six Pack, a team he put together when chasing his evil clone, Stryfe, back in time.

The Six Pack would be more than welcome in a Deadpool movie, given the brutality of their actions. Even if they can be regarded as superheroes, they don't shy away when it comes to killing their enemies.

The Six Pack was originally composed of Cable, Garrison Kane (another character the studio deemed too expensive for the first Deadpool outing), Grizzly, Constrictor, and Domino. Of course, the studio might still consider that it would be too expensive to have these characters appear onscreen through the entire movie.

But an introductory scene in which Cable is revealed, could also include them. Speaking of which"¦

X-Force

We know that an X-Force movie is on its way, and we know that Deadpool will be in it. It isn't certain, though, when it will arrive (we’ve heard sometime in 2017). If X-Force arrives before the Deadpool sequel, maybe they should pop in for a bit in his solo movie, to give the audience a sense of continuity. If X-Force arrives later on, what better way to introduce them than in a Deadpool flick?

Domino, Warpath, Cannonball, and Feral wouldn't take too much of Cable or Deadpool's screen time, so they wouldn't be too expensive for the studio. The money they would use to bring Colossus to life would be more than enough for the four mutants.