Bowser Koopa is quite probably the most well-known loser villain in the gaming universe. How many times has he failed to keep the princess for himself? And worse - in his first RPG, he had to join sides with Mario, that lowly plumber! He is definitely sad as a villain, but we love him anyway.

As a dueller... he's somewhat surprising. No butt-stomps, but he can summon Boos to scare his opponent, poison people with a gas cloud, hit things with his claws pretty hard and summon a giant mechanic Koopa to stomp his foe! And he has the power of the Work Pants. Sadly, he takes magic like a girl and severely lacks speed, but the King of Koopas still has had enough in his arsenal to claw his way into Middle, where he's been a respectable competitor- so long as he isn't facing a pink-clad girl with an umbrella.