Dragonlord

Dragonlord, sometimes referred to as Dracolord, is the main villain of the first Dragon Quest and the first major villain in the Dragon Quest series. He made his first appearance in the Mario series as one of the playable characters in the game Itadaki Street DS.

Background
In Dragon Quest (or Dragon Warrior outside of Japan), Dragonlord was the ruler of Charlock Castle and prior to the game he had stolen the Ball of Light to summon his evil monsters to invade the kingdom of Alefgard, he then kidnapped Princess Gwaelin. Throughout the game a nameless Hero goes on a quest to rid the land of his tyranny and save the princess. Despite his appearance of a physically weak humanoid sorcerer, it was revealed that he was in truth a large and powerful Dragon.

He also appeared as a monster in Dragon Warrior Monsters and a playable character in Itadaki Street Special.

Itadaki Street DS
He appears as a playable character in Itadaki Street DS. Items called Dragonlord Hat, Dragonlord's Robe and Dragonlord Staff are collectible items that can be equipped on customizable characters.

Fortune Street
Dragonlord returns as a default playable character in the sequel to Itadaki Street DS Fortune Street for the Nintendo Wii. He still has a similar appearance as in the previous game, however this time around his robe is lighter in color, the jewel on his necklace has spikes, his hat resembles bat ears rather than horns and most notably he now has a visible nose.

Captain N: The Game Master
He appeared in Captain N: The Game Master where he was portrayed as a dragon at all times. He was often featured as a villain in the series and appeared to be king of all dragons. Unlike in the games, his dragon form is red instead of purple.

Fortune Street

 * North American Official Site Bio: "The kingpin of monsterkind who wants the world plunged into darkness. True to his dastardly disposition, he's also a ruthless businessman."