The Super Mario Bros. Movie has been out for less than a month, and has already made animation history. With over $600 million already gathered from the box office, it's already the highest-grossing video game movie. Knowing Illumination's history with successful franchises, this likely guarantees a potential sequel sometime in the future.
As many Nintendo fans noted, The Super Mario Bros. Movie is full of Easter eggs referencing many recognizable Mario franchise figures. While some of them play major roles in the film's plot, others have brief cameos that delight Nintendo fans. However, these characters don't appear in the film, but may come up in a future sequel or spin-off.
10 Yoshi
Perhaps the only guarantee about a sequel to The Super Mario Bros. Movie is the debut of one of Mario's most trustworthy sidekicks, Yoshi. A post-credits scene for the movie finds a familiar-looking Yoshi egg cracking in the depths of Brooklyn's underground sewers. Earlier in the film, a herd of Yoshi race through a field during a montage sequence.
The appearance of Yoshi would make for a great Yoshi's Island-esque sequel, especially if like those spin-off games it explores Mario and Luigi's childhoods more. Or perhaps, they'll take on a similar story to Super Mario World, which served as Yoshi's debut on the SNES. Either way, fans can definitely expect to see this green dinosaur make its debut.
9 Wario & Waluigi
Many Mario fans were disappointed at the lack of Wario and Waluigi, the evil counterparts to Mario and Luigi, appearing in the film. While Waluigi has mainly only appeared in spin-off titles like Mario Party and Mario Kart, Wario has been the star of his own video game franchises, including Wario Land and the microgame-filled WarioWare.
The two characters' casting have also been the subject of debate across the Internet. Names like Danny DeVito or Pedro Pascal have not only been brought up by fans as the perfect Wario, but also by the film's voice cast. Other Internet fans have suggested comedians like Tim Robinson to play the role of Waluigi, which would certainly be hilarious.
8 Bowser Junior
At the end of The Super Mario Bros. Movie, Bowser finds himself the captive of Princess Peach, shrunken down and kept in a cage in her castle with only a piano to accompany him. This could potentially leave room for a new face to take charge of the Koopa army, and who better than Bowser's own son, Bowser Jr.?
Bowser Jr. first appeared in Super Mario Sunshine, spending most of the game masquerading as Shadow Mario. This could make for a fun subplot to a sequel film, getting to see Mario face off against a darker version of himself. It's likely Illumination would also cast a child actor, like Jacob Tremblay, to play the rambunctious child of Bowser.
7 Princess Daisy
The love story between Mario and Princess Peach is only slightly kicked off in The Super Mario Bros. Movie, with future films potentially leaving room for their relationship to grow. However, given that Luigi is now living with Mario in the Mushroom Kingdom, it'd be worthwhile for him to get his own love interest. The video games have that in Princess Daisy.
Furthermore, Daisy could be a good option to showcase Peach's backstory, with her original home potentially being Sarasaland, Daisy's kingdom. To complement Anya Taylor-Joy, Daisy could be voiced by another notable actress like Hailee Steinfeld, who has done plenty of voice work before, or even a more comedic actress like Rachel Brosnahan.
6 Rosalina
One of the standout characters in The Super Mario Bros. Movie is Lumalee, whose whimsical nihilism makes for a great recurring joke in the film. However, many fans noted that the existence of the Lumas in the film implies a potential appearance for Rosalina. The character debuted in Super Mario Galaxy as a maternal figure to the Luma race.
Interestingly, Rosalina's backstory in the Nintendo Wii game seems to have informed Peach's relationship with the Toads in this film, perhaps linking the two characters. The character certainly calls for an elegant voice actor to play the part of the galactic princess, such as Elle Fanning, Emilia Clarke, or even Wonder Woman herself, Gal Gadot.
5 Professor E. Gadd
Charlie Day's casting as Luigi excited many Mario fans who are hoping for a possible Luigi's Mansion film at some point in the future. The character certainly gets a moment reminiscent of the games during his escape from the Dry Bones in the Dark Lands. However, a certain scientist would make the perfect callback to the iconic ghost-catching series.
Professor E. Gadd has made numerous appearances in the Mario franchise outside the Luigi's Mansion games, including Mario & Luigi: Superstar Saga, with his inventions appearing in Super Mario Sunshine. The character would be absolutely perfect if voiced by an actor like Christopher Lloyd as a reference to his iconic role as Doc Brown.
4 King K. Rool
The Jungle Kingdom plays a significant role in The Super Mario Bros. Movie as an ally of the Mushroom Kingdom after Mario defeats Donkey Kong. Although the kingdom is certainly prime for a spin-off, one of the biggest villains of the Donkey Kong Country series could pose a threat to the Mushroom Kingdom in a potential sequel film.
King K. Rool is no stranger to adaptation, as he appeared as a recurring villain in the Canadian Donkey Kong Country animated series in the late 1990s. He would certainly rival Bowser, especially with an actor who could match Jack Black's energy like Will Ferrell, which would delight fans of his film The Other Guys who know the name "Gator."
3 The Koopalings
Of course, Bowser Jr. is an obvious choice for Bowser's underling in a future film, but another option is even referenced in the film. During a scene where Bowser plays piano, the name "Ludwig von Koopa" can be seen on the musical instrument. This references one of the seven Koopalings, who originated in Super Mario Bros. 3 on NES.
The Koopalings would make quite the adversaries of Mario and his friends, especially with Bowser currently a captive of Princess Peach. It'd be difficult to figure out the best cast for all seven of them, but they'd need some pretty loud comedic personalities among them, such as Alison Brie, Richard Kind, Taika Waititi, and Bill Burr as some key Koopalings.
2 Petey Piranha
Petey Piranha first appeared as a boss character in Super Mario Sunshine, and has made recurring appearances in the franchise ever since. Notably, the character was featured in titles like Super Smash Bros. Brawl, Mario & Luigi: Partners in Time, and New Super Mario Bros., making him a perfect choice for a potential opponent of Mario in another film.
Although it's unlikely for Petey Piranha to be a film's main antagonist, he would make a great, monstrous enemy for Mario and his friends to battle. Additionally, the character's lack of proper voice would probably save Illumination the cost of hiring another voice actor. Especially if the film takes after Super Mario Sunshine, this would be a fun sequence.
1 Lakitu
Many recurring Mario enemies appear in The Super Mario Bros. Movie, from Goombas, to Koopas, and even a blue-shelled Koopa that wreaks havoc in a Mario Kart scene. The film even features some lesser-known enemies from the series, like the Biddybud and King Bob-omb, as well as minions that haven't even appeared in the Mario games.
However, one iconic enemy from the franchise's history doesn't prominently show up: the Lakitu. In the original Super Mario Bros., the Lakitu drops Spikes (which do appear in the film) from the sky. It seems like quite the oversight, but perhaps Illumination plans for the character to make a bigger appearance in the future, voiced by someone like Bill Hader.