Bowser

Bowser, sometimes known as King Koopa, is a major character and the main antagonist of the Mario franchise. Bowser is a large, powerful, fire-breathing Koopa who leads the Koopa Troop, an antagonistic organization of turtle-like creatures, and has been the archenemy of the Mario Bros. since his debut in Super Mario Bros. He has repeatedly kidnapped or attempted to kidnap Princess Peach with the ultimate goal of defeating Mario and taking over the Mushroom Kingdom.