Bowser

Bowser is the king of the Koopas, and the main antagonist of the Super Mario series. He appears in the filename videos as well.

breakingbowser.mp3
Mario arrives at Bowser's Castle to stop him and Larry Koopa. He decides to defeat Bowser by mentally exhausting him, frustrating Bowser the longer it goes on, who seems to want Mario to defeat him. Bowser starts treating Mario like a baby, explaining things to him, but to no avail. Bowser decides that he's had enough and turns giant, but is defeated by the teamwork of Mario and Mary.

Trivia

 * Bowser seemingly has nothing to do with the Larry Koopa incident.
 * Bowser practically telling Mario to defeat him is mocking the axe at the end of the bridge for existing for that one purpose.