Dr. Ivo Robotnik, more commonly known as Dr. Eggman, is the main antagonist of the Sonic the Hedgehog franchise. He is the arch-nemesis of Sonic the Hedgehog the series' titular character.

The tyrannical ruler of the Eggman Empire, he is a mad scientist with an IQ of three hundred who repeatedly plans to conquer the world. During his villainous outings, he became obsessed with the idea of an entire world under his rule, utterly convinced with his twisted belief that the results of a world conquest orchestrated by him would make the world a better place and benefit all its inhabitants. Using his unmatched genius, Eggman began his plans, spending his entire life on his self-righteous mission.