Episode: "Imaginationland III” (s11e12)
Original Air Date: October 31, 2007

What evil cadre would be complete without the king of the koopas, Mario's eternal nemesis Bowser. Aside from some embarrassing cartoons in the early '90s, Bowser has always been a princess-napping buffoon, stumbling his way down lava pits, out of his castle (at least three occasions), and finally into the epic engagement to decide the fate of Imaginationland. Though viewers may not see him in the midst of the fray, it's safe to assume that he's either blowing fire, stomping, or being swung by his tail in spiked bombs.