In April 1990, Sega petitioned its research and development department, AM8, to create a character who would replace Alex Kidd as the company's mascot, as well as compete against Nintendo's flagship character, Mario. A caricature of Theodore Roosevelt was among the proposed designs, and combined with the idea of an egg-shaped character, it eventually became the basis of the visual design for Dr. Robotnik/"Eggman". In creating the "bad guy" for the Sonic series, the development team wanted a character who was "the opposite of Sonic"; a character who represented "machinery" and "development" to play on the then-growing debate between developers and environmentalists. The character was also designed to be easy for children to draw.
One of the concepts for the hero of what eventually would be known as Sonic the Hedgehog

The original English instruction manual for his 1991 debut game Sonic the Hedgehog described the character's full name as "Doctor Ivo Robotnik" while the Japanese version's instruction manual for the same game called him "Doctor Eggman". Then in 1999's Sonic Adventure, the character was called both "Doctor Robotnik" and "Doctor Eggman" in the English version, with all following English releases to date referring to him as "Doctor Eggman". Yuji Naka has explained that "Robotnik" is the character's real name while "Eggman" is a "common name taken after his shape." Despite this, the Japanese Sonic Channel profile listed his full name as unknown.