Kamek is Bowser’s right-hand Magikoopa, often responsible for aiding the Koopa King with spells, minion enhancements, and baby Bowser’s upbringing. He plays a crucial role in Yoshi’s Island, attempting to stop Baby Mario from reuniting with Luigi. A fun fact is that Kamek was originally meant to appear as a boss in Super Mario 64, but his role was scrapped, and elements of his character were later adapted into Paper Mario.

King Boo is the sinister ruler of all Boos and the main antagonist of the Luigi’s Mansion series, possessing an eerie intelligence and immense ghostly powers. Unlike regular Boos, he is not afraid of being looked at and instead uses illusions and deception to trap his enemies. A chilling fact is that King Boo’s true form, revealed in Luigi’s Mansion: Dark Moon, shows a dramatically larger size and more menacing appearance, emphasizing his growth in power over time.

Kooper is a friendly Koopa Troopa and a key party member in Paper Mario, joining Mario on his quest with his signature shell toss ability. He is an adventurous and eager young Koopa who dreams of becoming a great explorer like his idol, Kolorado. A fun fact is that Kooper's design closely resembles that of a regular enemy Koopa, making him one of the most unassuming heroes in Mario history.

Luigi, Mario’s younger brother, is often portrayed as the more timid and overshadowed sibling, though he has proven himself a hero in his own right, particularly in the Luigi’s Mansion series. His higher jump and slippery movement make him unique in gameplay. A quirky detail is that Luigi was originally just a green palette swap of Mario in Super Mario Bros., but over time, he developed his own personality, becoming a fan-favorite character.

Wario is Mario’s greedy and mischievous rival, often portrayed as a brawler with a love for treasure. He first appeared in Super Mario Land 2: 6 Golden Coins as the main antagonist but later became the star of his own games. A hilarious fact is that in WarioWare, Wario’s obsession with money extends to making microgames as a get-rich-quick scheme.

Toad is a loyal attendant of Princess Peach and one of the most recognizable characters in the Mario series, often providing Mario with assistance and guidance. Despite his small size, Toad has shown remarkable bravery in various games. An interesting fact is that Captain Toad: Treasure Tracker gave him his first starring role, where he proves that he can be a hero without even jumping.

Mario, the iconic plumber and hero of the Mushroom Kingdom, is known for his signature red hat, mustache, and incredible jumping ability. He has appeared in countless games, saving Princess Peach from Bowser and embarking on adventures across various lands. A surprising fact is that Mario was originally named "Jumpman" in Donkey Kong before being renamed for the real-life landlord of Nintendo’s warehouse.

Big Boo is a larger and more menacing version of the common Boo enemy, appearing in multiple Mario games, particularly in haunted house levels. Unlike smaller Boos, Big Boo requires special strategies to defeat, often needing Mario to find a way to make it vulnerable. A fun fact is that in Super Mario 64, Big Boo actually houses an entire level inside of it—Big Boo’s Haunt—making it one of the few enemies to serve as an entry point to a stage.

King Bob-omb is a regal, mustachioed Bob-omb who serves as the first boss in Super Mario 64, challenging Mario to a wrestling-style battle at the top of Bob-omb Battlefield. Despite his imposing size, he follows a strict code of honor, only fighting Mario in a fair contest. A neat fact is that in Mario Kart DS, King Bob-omb makes a surprise reappearance as a boss in the game’s mission mode, showing that his reign extends beyond platformers.

Petey Piranha is a massive, mutant Piranha Plant with wings, appearing as a boss in multiple Mario games. He is known for his enormous mouth and ability to spit goop, first debuting in Super Mario Sunshine. A strange fact is that in Mario Kart: Double Dash!!, Petey Piranha is actually one of the heaviest characters, despite being a plant.

Bandit is a sneaky, mask-wearing enemy often seen in Yoshi’s Island, known for its mischievous nature and tendency to steal items from the player before running away. Unlike most foes, Bandits don’t directly attack but instead rely on trickery, making them a unique adversary. An interesting fact is that in Yoshi’s Island DS, Bandits can be seen disguising themselves as Yoshis in an attempt to blend in, showing just how devious they can be.

Donkey Kong Jr. is the son of the original Donkey Kong and protagonist of Donkey Kong Jr., where he embarks on a quest to rescue his father from Mario, reversing the usual hero-villain dynamic. Unlike his father, he is more agile, using vines to climb and navigate levels. A fun fact is that despite his popularity in early Mario spinoffs like Super Mario Kart, Donkey Kong Jr. eventually faded from the series, with Donkey Kong (from Donkey Kong Country) seemingly replacing him.

Hookbill the Koopa is a giant, overweight Koopa boss from Super Mario World 2: Yoshi’s Island, serving as one of the game's more memorable encounters. Unlike normal Koopas, he can stomp the ground to shake the battlefield and must be flipped over before he can be damaged. An intriguing fact is that his hunched-over, droopy-eyed design makes him appear older than most Koopas, leading fans to speculate that he may be an elder among them.

Mailtoad is a lesser-known character who serves as the postal worker in Super Mario Galaxy, often delivering messages and gifts to Mario. His role, while small, is essential in keeping players connected with Princess Peach, who sends him letters throughout the game. A fun Easter egg is that sometimes Mailtoad will deliver humorous messages from Peach, teasing Mario about his adventures.

Princess Peach is the benevolent ruler of the Mushroom Kingdom, frequently kidnapped by Bowser but also a capable adventurer, particularly in games like Super Princess Peach. She is known for her elegance, kindness, and signature pink dress. A fun detail is that in Super Mario Bros. 2, Peach was the only character with the unique ability to float in the air, making her a fan-favorite choice.

Whomp King is a massive Whomp who serves as a boss in Super Mario 64, guarding the top of Whomp’s Fortress. Unlike regular Whomps, he can speak and expresses frustration about being walked on. A funny detail is that despite his power, he has the same weakness as regular Whomps—falling flat on his face exposes his back, making him easy to defeat.

Hammer Bro is a highly troublesome enemy that throws hammers in rapid succession, making him one of the most difficult foes in the original Super Mario Bros. games. These Koopas have also appeared as friendly characters in some spin-offs. A cool detail is that in Super Mario Galaxy, a much stronger version called Sledge Bro appears, capable of shaking the ground when it lands, showing the evolution of the enemy’s threat level.

Yoshi is Mario’s trusted dinosaur companion, known for his long tongue, flutter jump, and ability to eat enemies. He debuted in Super Mario World and has since become a beloved character with his own series. A cool fact is that Yoshi was originally meant to appear in Super Mario Bros. on the NES, but the developers couldn’t implement him due to hardware limitations.