Sega wanted a game capable of competing with Mario and a character to replace Alex Kidd as the company's mascot. Several character designs were submitted by its AM8 research and development department, including an armadillo (which then developed into Mighty the Armadillo), a dog, a Theodore Roosevelt look-alike in pajamas (which would later be the basis of Dr.Robotnik/Eggman's design), and a rabbit (intended to use its extendible ears to collect objects; these aspects were later incorporated into Ristar). Eventually, Naoto Ōshima's spiky teal hedgehog, initially codenamed "Mr. Needlemouse", was chosen as the new mascot. (Note that "needlemouse" is a direct translation of the Japanese word for hedgehog ハリネズミ (harinezumi).) Sonic's blue pigmentation waschosen to match Sega's cobalt blue logo, his shoes were a concept evolved from a design inspired by Michael Jackson's boots with the addition of the color red, which was inspired by both Santa Claus and the contrast of those colors on Jackson's Bad, while his personality was based on Bill Clinton's "Get it done" attitude. The character was created without the ability to swim because of amistaken assumption by Yuji Naka that all hedgehogs could not do so.
A group of fifteen people started working on the first Sonic the Hedgehog game, and renamed themselves Sonic Team. The game's soundtrack was composed by Masato Nakamura of the band Dreams Come True. Sega sponsored the group's "Wonder 3" tour, painting Sonic on the tour bus, distributing pamphlets advertising the game,and having footage of the game broadcast above stage prior to its release.
The original concepts had Sonic with fangs and in a band with a human girlfriend named Madonna, however a team from Sega of America led by Madeline Schroeder, who calls herself "Sonic's mother", "softened" the character up for an American audience by removing these, sparking a heated issue with Sonic Team, althoughNaka later admitted it was probably for the best. Sonic's appearance varies greatly depending on the medium and the style in which he is drawn. In the video games, Sonic's original design by Oshima was quite short and round, with short quills, a round body and no visible irises. Artwork featuring this design and drawn by Akira Watanabe was displayed on the package artwork for Sonic theHedgehog, and most subsequent Sonic video games featured similar designs.
When Sonic the Hedgehog 2 for the Mega Drive appeared, the proportions of Sonic changed. The original 1:2 head to height ratio became 1:2.5.
Beginning with Sonic Adventure, in 1998, Sonic was redesigned by Yuji Uekawa as a taller character with longer legs and a less spherical body, longer and more drooping quills, theaddition of shoe buckles, and green-colored irises. Further subtle changes to the character's design have been made in subsequent games. Spin-off media such as comics and cartoons have featured variations on all these video game designs, with restrictions set by the standardized model sheets.
 Actor portrayal
Different actors have provided the voice for Sonic in his game appearances. Sonicoriginally had a few voice samples in Sonic CD, but the actor is unknown. Sonic's first true voice actor was Takeshi Kusao for the arcade game SegaSonic the Hedgehog, with Junichi Kanemaru continually voicing the role beginning with the release of Sonic Adventure. In Sonic Unleashed, Sonic is voiced by Tomokazu Seki whilst in Werehog form. Sonic's first English voice actor was Jaleel White (betterknown to fans as Steve Urkel on the TV show Family Matters) in the three animated series Adventures of Sonic the Hedgehog, Sonic the Hedgehog (SatAM) and Sonic Underground. Sonic's first English game voice was provided by Ryan Drummond beginning with Sonic Adventure, a role he continued until 2004, when he was replaced by Jason Anthony Griffith, who previously voiced the character in the...