Mobius

Mobius is the planet that the Sonic the Hedgehog characters are from in the comic book series made by Archie comics (America) and Fleetway (Europe), and in all three American cartoons, including the light-hearted Adventures of Sonic the Hedgehog, the more serious ABC cartoon Sonic the Hedgehog (considered as "SatAM" by the Sonic community), and Sonic Underground.

Depictions of the planet vary from universe to universe. In SatAM and Archie, it's a future Earth, but consists of Mobians (animalistic beings) and is ruled by a dictator, Dr. Robotnik, who orginally went by the name of Julian Kintobor before he became a dictator trying to destroy all Mobian life, and trying to turn them into Robots (considered as "Robians") via roboticization. In Sonic Underground, the same kind of setup is used, but no reference to Earth is made (nor is Robotnik's first name particularly mentioned). In Adventures of Sonic the Hedgehog, the place is completely free, with Dr. Ivo Robotnik just trying time and again to take it over (and usually failing miserably).

It is also a rumor that in the newest Sonic cartoon (an anime), Sonic X, that the planet they were on before they got transported was Mobius; however, there is no substantial evidence to back up this claim, and since there has been virtually no mention of Mobius in the country it was made (Japan), many people do not believe it is intended to be that way.

Mobius is also been the home of Sonic in many fanfiction stories, fanart pieces, fangames, and in Sonic based role play.

Outside of Spinball and Mean Bean Machine, which were made to promote the cartoons, the Sonic video games are not intended to take place on Mobius; but instead on Earth.