Doctor Ivo Robotnik(ロボトニックRobotonikku), also known by his alias Doctor Eggman(ドクター・エッグマンDokutā Egguman), is a video game character and main antagonist of the Sonic the Hedgehog series created by Sega. Dr. Robotnik is a rotund, mad scientist with an IQ of 300 who plans to conquer the world, and is the evil de facto archenemy of Sonic the Hedgehog. His character designer is Naoto Ōshima, and while he has gone through several large appearance changes throughout the series, his design retains several basic characteristics, such as his egg-shaped body and his large mustache. Beside his scientific skilled mind, he is also very immature and tends to throw a temper tantrum mostly whenever his plans fail. He has appeared in almost every Sonic the Hedgehog game series and in all other media.