Between Sonic Adventure and Sonic Riders, most of Dr. Eggman's Badniks were given serial numbers with an "E" prefix (E for egg). These robots have been referred to colloquially as the E-Series.

List of E-Series robots from the Sonic games

Since Sonic Heroes, Eggman seems to have stopped giving his robots serial numbers, though many of them still go by the "Egg" prefix in their names. From this point, all Eggman robots no longer have E-numbers, which has been consistent since Shadow the Hedgehog.

Sonic X robots

In the Sonic X anime, Dr. Eggman's robots all have an E-Series number. While their numbers don't coincide with those of the game robots, they make no appearances in game canon, and (apart from the E-100 models) vice versa.


  • Ever since the Dreamcast era of the Sonic the Hedgehog franchise, the character of Dr. Robotnik has been called by his original Japanese name "Eggman" in Europe and the US. Along with his name change, his "Badnik" robots were from then on known as the E-Series (E for "egg") since the name "Badnik" no longer fit.
  • Since Sonic Rivals 2 on the PlayStation Portable, Eggman's robots have returned to being referred to as Badniks, even though the doctor himself hasn't gone back to using the name Robotnik. In a cutscene in Rivals 2, Eggman verbally uses the term "Badnik", something that has never happened in previous games.
  • In Sonic Lost World for the WiiU, Eggman has once again taken to referring to his robots as "Badniks".