Eggman's modern (right) and classic (left) designs.
Dr. Ivo Robotnik, also known by his nickname Dr. Eggman, is the main antagonist of the Sonic franchise. He is a mad scientist who desires to take over to world, and mainly serves as the arch-nemesis of the titular blue hedgehog. Thanks to all his heinousness, he has quite a few versions who fit as Shonen Villains.