King Koopa as the main antagonist, depicted as a green, alligator-like Koopa with a spiked shell and a crown. He is loosely based on both Bowser and Wart from the original games and serves as the tyrannical ruler of Dark Land and leader of the Koopa Pack. In the show, King Koopa frequently attempts to conquer the Mushroom Kingdom, capture Princess Toadstool, and steal ancient artifacts. He is known for his various aliases, disguises, and use of the Koopa Pack to carry out his evil schemes