Bowser (クッパ Kuppa, "Koopa")^[1] or King Koopa is a fictional character and the main antagonist of Nintendo's Mario franchise. In Japan, the character bears the title of Daimaō (大魔王 Great Demon King, lit.).^[2] In the United States, the character was first referred to as "Bowser, King of the Koopa" and "The sorcerer king" in the instruction manual.^[3] Bowser is the leader and likely the most powerful of the turtle-like Koopa race, and has been the archenemy of Mario ever since his first appearance, in the game Super Mario Bros.

His ultimate goals are to kidnap Princess Peach, defeat Mario, and conquer the fictional Mushroom Kingdom. Since his debut, he has appeared in almost every Mario franchise game, usually serving as the main antagonist. Currently, Bowser is voiced by Kenny James. In addition to his usual animated and video game appearances, he also appears in the 1993 highly criticized live-action film, where he is portrayed by Dennis Hopper.