Debuting in the first game of the series, Sonic the Hedgehog, he was shown attempting to collect the Chaos Emeralds and turn all of the animals inhabiting the land into robots. He is a self-proclaimed or certifiable genius with an IQ of 300. His fondness for mechas has made him a renowned authority on robotics. Ultimately, Eggman's goal is to conquer the world and create his ultimate utopia, Eggmanland (alternatively known as the Eggman Empire and Robotnikland). When Sega had petitioned its research and development department to create a character who would replace Alex Kidd as its company mascot, a caricature of U.S. President Theodore Roosevelt was also among the proposed designs. It lost to Sonic the Hedgehog, but eventually became the basis for Dr. Eggman instead.
Developed as a replacement for their existing Alex Kidd mascot, as well as Sega's response to Mario, his first appearance was in the arcade game, Rad Mobile (as a cameo), before making his official debut in Sonic the Hedgehog (1991). Sonic's greatest ability is his running speed, and he is known as the world's fastest hedgehog.Using the power of the seven Chaos Emeralds, he becomes Super Sonic and achieve even greater speeds. Typically, Sonic—usually along with some of his friends, such as Tails, Amy, and Knuckles—must stop Eggman and foil any plans of world domination. The first game in the series, released in 1991, was conceived by Sega's Sonic Team division after Sega requested a mascot character. The title was a success, it spawned many sequels, and it transformed Sega into a leading video game company during the 16-bit era in the early to mid 1990s.
He is able to use his two tails to propel himself into the air like a helicopter for a limited time. Yasushi Yamaguchi, originally the main artist and zone designer for Sega's Sonic Team, designed Tails for an internal competition for a sidekick to Sonic. His first appearance was in Sonic 2 for the Game Gear, where he was kidnapped by Robotnik for a "hefty" ransom, and was first made playable in the Genesis version of Sonic the Hedgehog 2. Tails has appeared in almost every Sonic game since his first appearance. Tails also starred in two solo spinoff games for the Sega Game Gear in 1995 - Tails' Skypatrol, and Tails Adventures.Frequently portrayed as a sweet-natured and humble fox. Tails used to be picked on because of his twin tails, before he met Sonic.Tails has a very high IQ and has great mechanical ability.