Mobius

Planet Mobius is the home planet in many continuities of Sonic the Hedgehog and is referenced as the home planet in the Sonic the Hedgehog animated series, Sonic the Hedgehog Archie comics series, Sonic the Comic, Adventures of Sonic the Hedgehog and Sonic Underground series. The earlier Western versions of the games also had the game continuity set on Planet Mobius, however, the Japanese games always took place on Planet Earth, since Sonic Adventure, all versions of the games have followed to the Japanese continuity.