After years of speculation, writer/director Todd Phillips has confirmed that a sequel to his Academy Award-winning movie Joker is in development, with Joaquin Phoenix confirmed to be returning to the role (which earned him his first Academy Award win for Best Actor).

Joker was one of the biggest movies of 2019, grossing over $1 billion (via Box Office Mojo) and if the fan reaction to the sequel's announcement is any indication, Joker 2 could be an even bigger success. Those particularly on Twitter seem to be clamoring with excitement, with many expressing their joy through memes or their tweets.

Excitement At Joaquin Phoenix's Return

While the box office success of Joker made a sequel feel inevitable, it was far more uncertain if Joaquin Phoenix would even be interested in returning to the role of Arthur Fleck.

With Phillips himself sharing a photo of Phoenix looking over what can be assumed is the script for Joker 2, fans, like @ErikDavis, were able to exhale and share their relief that he would be reprising the role.

The Fall Out Boy Cinematic Universe

The Joker sequel's subtitle Folie à Deux not only means "a madness shared by two" but is also the name of an album by rock band Fall Out Boy. After releasing Folie à Deux, the band went on hiatus for four years before returning with Save Rock and Roll.

It's unlikely that Todd Phillips selected the subtitle because he's a massive FoB fan but the announcement was certainly met with plenty of amusement from fans, such as @shutupholden, that made the connection.

Imagining Potential Movie Posters

Popular internet artist @BossLogic wasted little time in sharing his take on what the movie's title may mean. Based on the title, it looks like the sequel might be exploring Arthur's mental health in more depth.

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However, that hasn't stopped fans underneath the comment section from theorizing about whether the "madness between the two" could be referring to another character - or even another Joker (such as a reference to Cameron Monaghan's Gotham Joker, the Joker featured in the Arkham series of video games, or even Barry Keoghan's recent take on the iconic character).

Fan Casting a Second Joker

Even before Joker 2 was announced, actor Willem Dafoe has been vocal in his desire to play the Joker and even appear on-screen alongside Phoenix's Joker Arthur Fleck. With Folie à Deux confirmed to be the sequel's title, fans, like @ScratchAE_, are wondering if Todd Phillips taking Dafoe up on the offer.

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Since the first movie ended with Fleck having inspired chaos and plenty of imposters, the thought of him being confronted by a second Joker has remained a popular theory.

"Somehow He Returned"

Initially, Joker seemed poised to be a one-off movie that wasn't interested in sequels or franchise tie-ins. While Todd Phillips and Joaquin Phoenix are both returning, fans, like @filmdaze, couldn't resist poking fun at the apparent about-face by tying in Star Wars: The Rise of Skywalker's infamously lazy explanation about the return of Emperor Palpatine.

RELATED: 10 Questions Fans Still Have About Star Wars: The Rise Of Skywalker

While the movie won't have quite as much explaining to do about the Joker's return, fans will have high expectations that the sequel maintains the quality and themes that made Joker so successful.

Just Add Danny Glover

@Lons suggested that the Joker sequel should just copy everything from Predator 2 starring Danny Glover, but this time swapping the Joker in for the Predator. While there's zero chance of that happening, it does bring to mind the pressure Joker 2 is under to match or exceed the expectations set by the first movie.

Predator 2 may be more of a cult classic among fans now, but it was a major disappointment when it was first released, footsteps that Todd Phillips and co. will absolutely be trying to avoid walking in.

Picturing Willem Dafoe In The Movie

Many fans, such as @pattynest, voiced their approval at the thought of Willem Dafoe appearing alongside Joaquin Phoenix but one went so far as to imagine what a Dafoe Joker could look like.

With his piercing eyes and striking facial features, the photoshop makes it even easier to imagine Dafoe fitting right into Todd Phillips' more grounded, realistic approach. There's no telling what direction they may take the story, but casting Dafoe isn't out of the realm of possibility and that certainly has many fans getting their hopes up for this bit of fan casting.

Happy To Have Him Back

While the movie itself garnered mixed reactions, Joaquin Phoenix's performance was met with near-universal acclaim, even winning him the Best Actor Academy Award. A reluctance to appear in sequels, a selective filmography, and other factors all made a Joker sequel seem unlikely so the confirmation that Phoenix is returning is a massive reason fans, such as @realsupes, are so excited for a sequel.

His high standards for the roles he chooses have also helped inspire faith among fans that the sequel will be up to par and will feature yet another unforgettable performance from Joaquin Phoenix as Arthur Fleck.

"It's Jokin' Time"

Morbius continues to be the gift that keeps on giving for fans of all the memes the movie has produced. With the news of the Joker sequel coming days after Morbius memes willed the movie back into theaters with dismal results, many fans, such as @Avast_o, braced themselves for another disaster that only resulted in more internet fodder and memes.

It may be Morbin' time right now but everyone will be watching and hoping for better results when Joker 2 finally does hit theaters.

The MCU vs. DC Battle Rages On

Many people argued that a sequel to Joker was unnecessary because of where the story ended and everyone involved in the movie's insistence that it would be a singular, self-contained story.

As @supersymmetry_I pointed out, just because something is "unnecessary" doesn't always mean it's not going to happen, drawing attention to the extensive slate of sequels, spin-offs, and more currently planned as part of the massive MCU. No matter what projects DC or the MCU continue to develop, fans will continue to debate which one truly is superior.

NEXT: 10 Movies That Shouldn't Get Sequels, According To Reddit