Sources describe Doctor Robotnik as a self-proclaimed or certifiable genius with an IQ of 300 and his fondness for robots has made him a renowned authority on robotics. Ultimately, Robotnik's goal is to conquer the world and create his ultimate utopia, Eggmanland (alternatively known as the Eggman Empire). He selfishly never gives up on this matter, and does not care for others' opinions.
He considers those who would interrupt his plans a prime threat. His abominable laughter and maniacal declarations contrast his self-professed softer side, as a romanticist, feminist, and gentleman. Despite his intelligence, Robotnik is terribly immature, prone to childish emotional fits when he is not getting his way. Although Sonic has always ruined his evil plans, Robotnik begrudgingly holds a secret respect for his determination.
In a story line presented in UK publication Sonic The Comic during the '90s, Dr. Robotnik was originally named Dr. Kintobor. A genius in his time, he was the only human to be able to cross to the planet of Mobius from Earth. He was accidentally responsible for giving Sonic The Hedgehog his speed during a failed experiment on the hedgehog, which also destroyed Kintobor's lab. During the failed experiment, Kintobor also was transformed changing from being quite thin and kind to the evil fat nemesis. Vowing revenge on Sonic and the world he inhabits, Kintobor took up the alias, Robotnik, the reverse of his real name.
In the English version of the games, Dr. Robotnik has was first voiced by Deem Bristow and until his death. Starting with Shadow The Hedgehog, he's been voiced by Mike Pollock.
In other media, starting with Adventures of Sonic The Hedgehog, he was voiced by British blues singer Long John Baldry; in Sonic The Hedgehog (Sonic SatAM), he was voiced by Jim Cummings; Gary Chalk voiced him in Sonic Underground; and in the Sonic OVA, he was voiced by Ed Niel.
- "Robotnik" means "worker" in Polish language.
- In one of the prerendered cutscenes in Sonic Unleashed for PS3 / 360, it can be seen that Robotnik owns a Sega Dreamcast.