King Bowser Koopa, often simply called Bowser and sometimes referred to as King Koopa, is the main antagonist of the Mario series and the King of the Koopa.
He has kidnapped or attempted to kidnap Princess Peach several times to take control of the Mushroom Kingdom.
He has also attempted to conquer the entire Mushroom world, as well as the entire universe.
Despite his evil side, he has sometimes helped the heroes of the Mushroom Kingdom against common threats and has participated with them in many sporting events in spin-off games.
