Several main characters appear in the Mario series, as enemies, friends, and other miscellaneous roles. Some of the more notable ones are listed here.

Mario

Mario is the main character in the Mario series, starring in games dating back to the early 80s.

Originally appearing in the arcade Donkey Kong game, Mario has gone through several graphical changes, but he remains the same plumber from Brooklyn that many grew up to know.

While he was known as Jumpman for a short time, when he was found to bear a striking resemblence to a Nintendo of America employee, he gained a new name -- Mario. Donning a red hat, blue overalls, and a red turtleneck, Mario has been through many adventures -- most notably, and often, saving Princess Peach.

Princess Peach

Known simply as the Princess, Peach became known worldwide by her Japanese name around the time of Super Mario Bros. 3's release. Having been captured numerous times by Bowser, Peach has called upon her hero, Mario, several times to rescue her. Peach has also appeared in several other games in more relaxing roles, such as being playable characters in Mario Party games, Super Smash Bros. Melee, and other games.

Luigi

Luigi is known as Mario's brother, but is often shunned because of his lack of starring roles in games. Yet, Luigi has been playable in several Mario games, and has taken the spotlight in Mario is Missing, and more notably, Luigi's Mansion.

Luigi is taller than Mario, and in many games, he'll slide a bit more on the ground. Luigi is easily identified by his green hat, green shirt, and blue overalls.

Bowser

Known as the main villain in the Mario series, Bowser has been tormenting Mario and the citizens of the Mushroom Kingdom for years.

With his army of Koopa Troopa and other baddies, Bowser (known as King Koopa in Japan) tries to keep Mario away from his castles. Usually choosing to kidnap Peach, Bowser has also made appearances in other roles, even abandoning the villain role in other games, such as Mario Tennis.

Toad

Toad is seen in various roles throughout the Mario series. Appearing in Super Mario Bros. (known as the mushroom retainer) to tell Mario that "our princess is in another castle," Toad became a playable character in Super Mario Bros. 2 (US) and has since been seen performing oddjobs. In some games, Toad serves as a guide to the player, while in others, he is a playable character.