Mario is one of Nintendo's biggest franchises ever since the dawn of gaming in arcades with Donkey Kong in 1981. Eventually, the series transitioned to home consoles with Super Mario Bros in 1985, and has become a mainstay of Nintendo's intellectual property. Most recently, the mainline series expanded onto Nintendo Switch with Super Mario Odyssey.

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For almost forty years, Mario has slowly become an icon of video game history. Over those years, there have been plenty of baddies that have stood in the way of Mario's attempts to rescue the princess or others. These villains from across the Mario franchise are some of the toughest, and most complex, the series has had to offer.

10 Il Piantissimo

Il Piantissimo confronting Mario in Super Mario Sunshine

Those who have played Super Mario Sunshine likely have strong memories (and probably negative feelings) about the recurring rival of Mario, Il Piantissimo. This character appears in several stages of Sunshine challenging Mario to a race. While his confidence can be annoying for some players, there's actually a deeper reason behind his competitiveness.

By talking to some locals in Pianta Village, players will learn that Il Piantissimo's outsider nature and attitude has made him a social outcast. As a result, he's become bitter towards people who won't step up to his challenges, which drives his passion to race Mario. While he's definitely earned this social position, it wouldn't hurt for people to be a bit nicer to him.

9 The Shadow Queen

The Shadow Queen holding Shadow Peach in Paper Mario: The Thousand Year Door

The Shadow Queen is a mythological figure in the Paper Mario universe, serving as the final boss of Paper Mario: The Thousand-Year Door. The queen is the creator of the crystal stars that Mario collects throughout the RPG. However, she was defeated by a team of four characters who sealed her spirit in her Palace of Shadows.

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In the events of The Thousand-Year Door, the Shadow Queen is revived by Beldam after capturing Princess Peach. Peach is used as a vessel for the Shadow Queen, offering Mario a chance to serve her. Once Mario refuses, the Shadow Queen presents her true form, but Mario is empowered with the goodwill of all the people he's saved and defeats her.

8 King Boo

King Boo appearing on a TV screen in Luigi's Mansion: Dark Moon

Mario's brother Luigi takes center-stage in the Luigi's Mansion franchise, becoming an amateur ghost-hunter and teaming up with a scientist named Professor E. Gadd. King Boo serves as the main antagonist of the game, creating the titular mansion in the series' first game to enact revenge on Mario and Luigi for capturing Boos in earlier games.

However, it's King Boo's conflict with E. Gadd that really drives his evil actions in the franchise. It's E. Gadd's capture of Boolossus prior to the events of Luigi's Mansion that makes King Boo driven to sabotage E. Gadd's ghost-busting duties. King Boo's return in Luigi's Mansion: Dark Moon is even a result of E. Gadd selling the portrait of King Boo.

7 Wart

Wart burping bubbles in a remake of Super Mario Bros 2 on Gameboy Advance

Before Super Mario Bros. 2 was a Mario game, it was a Famicom-exclusive title known as Doki Doki Panic. The game retained the same villain as Super Mario Bros. 2, Wart, though in this game he goes by the name Mamu. In that game, Mamu takes control of a dream machine, creating chaos in the dreams of the Muu people.

In Super Mario Bros. 2, Wart serves a similar purpose to Mamu, though the game's dream-like nature is a twist after defeating the game. Wart's plan is to conquer Subcon, the world of the game, until he's stopped by Mario, Luigi, Princess Peach, and Toad. Strangely, in the Game Boy Advance remake of the game, Wart's voice resembles that of Wario.

6 Donkey Kong

Donkey Kong standing with Pauline in the original arcade game

As the first antagonist of the Mario franchise, Donkey Kong has played many roles in the series. Often, he stars in his own franchise of sidescrolling games, like Donkey Kong Country, but in the original arcade title, he was once the pet gorilla of Mario, a.k.a. Jumpman. Rebelling against his master, Donkey Kong kidnapped Mario's girlfriend Pauline.

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However, retcons in the Donkey Kong Country series establish that the pet gorilla in these games may have actually been Cranky Kong. Despite this confusion, Donkey Kong has reprised his role as a boss character in games like Punch-Out!! and the Mario vs. Donkey Kong series, the latter of which finds him at odds with Mario over wind-up toys.

5 Cackletta

Cackletta standing with Fawful in Mario & Luigi: Superstar Saga for the 3DS

Cackletta appears as the main antagonist of Mario & Luigi: Superstar Saga, the fan-favorite entry in the Game Boy Advance RPG. Cackletta, a witch hailing from the Beanbean Kingdom, steals Princess Peach's voice in order to use it to harness the power of the Beanstar. Unfortunately, this earns the ire of the heroic Mario Brothers.

However, Cackletta's plan was foiled ahead of time by Toadsworth, who replaced Peach with Birdo in disguise. Therefore, the voice that Cackletta steals is not truly Peach. However, Cackletta does help springboard the villainous arc of Fawful, her follower who becomes the primary antagonist of Bowser's Inside Story.

4 Kamek

Kamek screaming in Yoshi's Island

Kamek is a recurring minion in the mainline Mario franchise, but the magic-using underling of Bowser plays an important role in the Yoshi series. Prophesizing that Mario and Luigi would create trouble for the Koopa Army, Kamek attacked the stork delivering the twins to their parents, inadvertently letting Baby Mario be discovered by Yoshi.

Throughout the first Yoshi's Island game, Yoshi and Baby Mario team up to rescue Baby Luigi, who is still in the possession of Kamek. However, Kamek is still just an underling in Yoshi's Island, making way for a final boss battle with Baby Bowser. Nevertheless, the character continues to terrorize Yoshi in future Yoshi series titles.

3 Bowser Jr.

Bowser Jr. holding a paintbrush in front of Peach in Mario Sunshine

Aside from Il Piantissimo, Super Mario Sunshine also introduces Bowser Jr. to the Mario franchise. As the son of Bowser, Bowser Jr. disguises himself as Shadow Mario and kidnaps Princess Peach, who he believes is his mother. Nevertheless, the truth of Bowser Jr's parentage remains a mystery in the Mario series.

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Although Shigeru Miyamoto once claimed that he is Bowser Jr's mother, the character's desire for a family remains a driving force of the character in the games. Nevertheless, Bowser Jr happens to find it with the Koopalings, seven other minions of Bowser, who were originally stated to be Bowser's children, but Miyamoto also disconfirmed that.

2 Bowser

Bowser standing in front of his warship in Super Mario Galaxy

Bowser has been Mario's primary antagonist ever since the original game on NES in 1985. His rivalry with Mario is a never-ending conflict, but it does have an origin way back in their childhoods. In Yoshi's Island, Baby Bowser is still the boss of Kamek, ordering him to kidnap Baby Mario & Luigi to thwart their future roles in Bowser's demise.

Baby Bowser also plays a significant role in the time-traveling RPG title Mario & Luigi: Partners in Time, kidnapping Baby Peach at the beginning of the game. However, Baby Mario & Luigi team up with their older selves to thwart Bowser yet again. Unfortunately, Bowser rarely succeeds in his attempts to kidnap the princess or capture Mario and Luigi.

1 Count Bleck

Count Bleck posing in the Void with Nastasia

By far one of the most fascinating bosses to ever grace the Mario franchise is Count Bleck. The 2D character appears in the Wii title Super Paper Mario, forcing Peach to marry Bowser and cause a rift between dimensions. However, it's his backstory before the events of Super Paper Mario that makes him such a compelling villain in the game.

Count Bleck was a young man named Blumiere, who fell for a girl named Timpani. His father, however, forbid their love and banished Timpani, turning her into a pixel named Tippi, Mario's ally in the game. Heartbroken, Blumiere destroyed his dimension, believing life was worthless without her, until they're eventually reunited in the events of Mario's adventure.

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