Bowser

Bowser is a giant turtle who is usually Mario's arch-nemesis. He is the leader and king of the Koopa Troop army, and likes to capture Princess Peach or try to conquer the world, although his plans almost always fails, and often needs the help of SuperMarioGlitchy3. Bowser has been shown to have used other methods of destroying Mario as well, such as creating four Mario robots & giving people nightmares with a crystal stone.