Although the west has known him as Dr. Robotnik in the many incarnations of Sonic’s adventures (in both animation and videogames), the evil doctor’s original Japanese name has always been Dr. Eggman (due to the characters appearance). This also explains why many of the bosses and levels of the games in western territories had Egg in the title (The Egg-O-Matic, Death Egg Zone, etc). For the Dreamcast games and the Sonic X animated series the character retained his original Eastern name.

Later seasons of Sonic X would follow the storylines of the two 3D 'Adventure' games, originally released on the Dreamcast, as well as the multi-format game Sonic Heroes.