Ensemble Dark Horse / Super Mario Bros.

Given its status as a Long Runner, the Super Mario Bros. series was bound to get more than a handful of popular characters.

Main series characters

• Bowser's original seven children, the Koopalings, were a well loved Quirky Miniboss Squad that appeared before being replaced by Bowser Jr. Their surprise return in New Super Mario Bros. Wii made many nostalgic fans happy, even if some were annoyed that they appeared in so many games after that. Among the seven, Roy, Ludwig, and Iggy are standout examples. Roy, for being portrayed as "the cool one" of the group, Ludwig, for his smug attitude, and Cultured Badass styled design, and Iggy for his Laughing Mad personality as well as having some of the most creative boss battles in the series.
• Waluigi started out as a character solely to mirror Mario and Wario's rivalry by giving Luigi an enemy, completely lacking a personality beyond being overconfident and narcissistic. Since then, Waluigi has steadily increased in popularity over the years, even earning himself several appearances in the Super Smash Bros. series as an Assist Trophy. The biggest reason he's so popular is thanks to Brawl in the Family, where the fans of the series were able to see Waluigi in a different (and crazier, and funnier) light. He also became more of a mischievous trickster with flairs of Tragic Villain and Butt-Monkey thrown in as more games came out to give him a better degree of characterization than just "rival to Luigi", got some awesome music and stages to his name (particularly Waluigi Pinball in Mario Kart DS), and was given increasingly hilarious mannerisms and roles in the games he appeared in (even with a plot-important role in Dance Dance Revolution Mario Mix). All of this combined with his early years as The Scrappy fading steadily into the realm of distant memory have earned him so much more positive reception in recent years that demand for him to be included as a playable fighter in Super Smash Bros. or even given his own game to star in is prevalent across the internet.
• Toadette. She initially was just a simple Distaff Counterpart made to partner with Toad in Mario Kart: Double Dash!!, and her appearances after would only be shifted to spin-offs and supporting roles. Despite that, she still managed to gain a sizeable fanbase with many people liking her adorable design and pleasant personality. Nintendo seems to have notice this, as she would go on to appear in Super Mario Odyssey, her first appearance in a mainline game, and later be full on Promoted to Playable in New Super Mario Bros. U Deluxe and Super Mario Bros. Wonder, much to everyone's delight.
• Pauline has historically been a bit character in the Mario series, despite being important in a meta sense. She has, however, long sported a small but loyal fanbase who want her to appear in more games such as Mario Kart. Her reappearance in Super Mario Odyssey not only pleased many of her old fans, but earned her plenty of new ones thanks to her newfound independent streak compared to her previous appearances and dazzling stage presence and singing voice, leading many to predict (and desire) for her to effectively become "the new Rosalina" by becoming a staple in the Mario spinoff titles or even staying a recurring character in the main series. So far, Pauline made her playable debut in Mario Tennis Aces as a post-release playable character, was added into the gacha of Mario Kart Tour via a special event, was part of the base roster in Mario Golf: Super Rush, and joined the cast of Mario Kart 8 Deluxe in the Booster Course Pass DLC.
• Blue Toad managed to prove himself as this when New Super Mario Bros. U Deluxe was announced. When the game showed that its default roster included Mario, Luigi, Yellow Toad, Toadette, and Nabbit, tons of people voiced their concern over what happened to the blue-capped retainer. Fortunately for them, he would later be shown to still be in the game, albeit under the same spot as Yellow Toad.
• At least in Japan, Birdo (or Catherine, as she's known in Japan) is a very beloved character, mainly due to her Evil Diva personality, Anti-Villain nature of wanting to be loved, and effectively being the face of the American Mario fandom in Japan. Her popularity in Japan led to her becoming a Breakout Character with major prevalence in Mario spin-offs, including being a boss in Super Mario RPG and Mario & Luigi: Superstar Saga, becoming a recurring character in Paper Mario games post-Sticker Star, and even being a major character in Captain Rainbow.

RPG characters

• Popple takes this status due to being an amusing Ineffectual Sympathetic Villain who keeps trying and failing to best the Mario Bros. People rejoiced when they discovered his return in Mario & Luigi: Dream Team, and even though he Took a Level in Jerkass, he's still well-liked in both appearances for the comedy factor alone.
• Super Paper Mario has Mr. L, despite clearly being a brainwashed Luigi. His cocky attitude and Brobot fights have made him pretty popular, not to mention the admittedly cool Evil Costume Switch.
• Super Mario RPG gives us Geno, otherwise known by his true name, ♥♪!?. A Star Spirit who "serves a higher authority" possessing a wooden doll, Geno increases the doll's size to a human proportion, and brings all its weapons with him, along with some awesome magic. Throughout the game, his abilities range from "shooting a cannonball from his elbow" to "launching his fists at enemies" to "replacing his hands with guns and firing stars" to "morphing into a cannon and shooting a tiny sun". Fans have been begging for him to make another appearance anywhere, but his only appearances so far have been a cameo in Mario & Luigi: Superstar Saga (which was removed from the remake) where he explains the rules for the Star 'Stache Smash minigame, and a Spirit cameo in Super Smash Bros. Ultimate. When his Mii Gunner costume was introduced in Super Smash Bros. for Nintendo 3DS and Wii U, his fans were ecstatic to see that through the sheer will of the fanbase, he was deemed relevant enough to be represented at all in such a blockbuster Massive Multiplayer Crossover. In Ultimate, the Mii Gunner costume initially had yet to see the light of day, even though Square Enix costumes appeared alongside the Dragon Quest Heroes, giving Geno supporters hope that in future DLC, he can finally make another playable appearance...only for the costume to actually be added alongside Final Fantasy VII's Sephiroth, to the dismay of his fanbase.
• Lady Bow in Paper Mario 64, despite being one of eight party members and not given any more story importance than the rest of the group, became the most popular for her fun personality, Creepy Awesome vibe, and useful abilities in gameplay. It is most likely because of this popularity that whenever future Paper Mario games have done a Call-Back to the first game, Bow is almost always the one representing the game. For example, she and Parakarry are the only party members from the first game to get The Cameo in The Thousand-Year Door, and she is also the only party member to show up on merchandise in Francis's room and on other posters in Super Paper Mario. This is helped by her not having a clear Expy in The Thousand-Year Door (for example, Goombella is very similar to Goombario, Koops is similar to Kooper, etc). The closest she has is Vivian, who carries over her invisibility ability, but otherwise the characters have so little in common that most don't consider Vivian an actual replacement.
• Also from Paper Mario 64, out of all the bosses who guard a Star Spirit, The Koopa Bros. and Tubba Blubba seem to be the most popular of the bunch, mainly due to being some of the only bosses who actually make a reoccurring presence before their actual fights. The Koopa Bros. are especially popular due to being a major Teenage Mutant Ninja Turtles shoutout, and the music associated with them and their boss fight, meanwhile Tubba Blubba gets points for being a sympathetic Anti-Villain.
• Vivian and Doopliss from Paper Mario: The Thousand-Year Door are this. The former for being an Anti-Villain who is constantly mistreated by her sisters, which she eventually has had enough of and makes her switch sides to fight alongside Mario. It also helps that she is really cute and arguably one of the best partners in the game. The latter is appreciated for being a villain who is both savvy and a walking, talking Funny Moment. The two of them are often voted the most popular characters in the game and frequently get requested to return in future installments.
  • Vivian's popularity may also be partially explained by her being canonically transgender in the original Japanese version and most European translations. Since trans characters in video games aren't too common and Vivian's sisters straight up bully her by misgendering her in the Japanese version, a lot of LGBT players would really sympathize with her.
• From the same game, Flavio. Initially, he was loved because of being haughty and arrogant, yet endearing, especially since nobody else in-game likes him. His popularity skyrocketed years after the game's release when it was discovered that, by using a few glitches to open up shortcuts to Keelhaul Key and Poshley Heights early, Flavio can be your guest in the party permanently, resulting in him showing up at particularly random times and places during cutscenes.
• Goombella's been getting a fairly decent following in recent years for being a Badass Adorable Bookworm who provides plenty of the game's gut-busters through her Tattles. It also helps that she has the Multibonk like Goombario before her, enabling her to dish out some serious punishment. She even got a cameo in Sticker Star's localization that wasn't there in the original, alongside Parakarry.
• Mizzter Blizzard from Paper Mario: Sticker Star is this due to being a Tragic Monster who also happens to be the only character in the game with a more noticeable characterization. To a lot of fans, he's one of the few redeemable things about the game.
• The Massifs in Mario & Luigi: Dream Team, with their Large Ham personalities, their generally badass attitudes, and their penchant for talking about BEEF.
• Paper Mario: Color Splash has the Shy Guy on the Sunset Express that can be talked to. By questioning his role as a member of Bowser's army he acts as a rare example of What Measure Is a Mook? in the Mario series and a deconstruction of a Punch-Clock Villain. His death should you end up fighting him later on in the game is also a tear jerker.
• Birdo's appearance in Color Splash is also met with praise thanks to being both funny and featuring a reference to Doki Doki Panic.
• The Phantom (Tom Phan) in Mario + Rabbids Kingdom Battle, for his epic opera song mocking Mario and his franchise's cliches.

Yoshi characters

• Yoshi's Island has Raphael the Raven, a boss character that proved popular enough with the fans that he reappeared in Paper Mario 64 with a Heel–Face Turn despite becoming a constellation in his original game. He also got his own trophy in Super Smash Bros. Melee.

Donkey Kong characters

• DK64 gave us Chunky, who is liked more than his younger brother Kiddy from Donkey Kong Country 3: Dixie Kong's Double Trouble! for having a more developed personality.
• Lanky is the most popular of the Kongs introduced in DK64 due to his uniqueness, fun personality and the novelty of playing as a different type of ape.
• Since then, though, the latest DK darkhorse seems to be Funky, who has been the fourth character in DK: King of Swing and DK: Jungle Climber, was unlockable alongside Diddy in Mario Kart Wii, and got an entire mode dedicated to playing as him in the Switch rerelease of Tropical Freeze, with its logo becoming a meme on par with "Featuring Dante from the Devil May Cry series".
• Mad Jack, the Frantic Factory boss of DK64, is well-remembered for his terrifying nature.
• Among all the bosses in Donkey Kong Country Returns, Colonel Pluck is quite popular for many reasons, he's the only boss that briefly breaks from the Tiki's mind-control, he pilots a giant mech after every other boss was more supernatural in nature, and he's a chicken putting up a good fight against the Kongs.
• Bashmaster from Donkey Kong Country: Tropical Freeze is quite popular for his intense boss theme and looks a lot more realistic than most of the animals, making him look even more menacing.

Wario characters

• 5-Volt was initially just a cameo in the Game Over screen of WarioWare: Twisted!, but eventually made her way up to a supporting character, became the main obstacle of Game & Wario's "Gamer" mode, and finally got her own stage to host in WarioWare Gold (in addition to "Gamer" returning as an extra mode) alongside the likes of series mainstays such as Mona and Dr. Crygor. Not only is she liked due to her surprisingly creepy behavior in "Gamer", but also due to her depiction outside of that segment, as a pretty lady who's just as much into Nintendo as her son is, if not more so.

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