"Early Sonic canon" is a catch-all term that refers to various similar yet distinct publications and continuities in the Sonic the Hedgehog series prior to the release of Sonic Adventure, when the original Japanese storyline overtook and forced the abandonment of the Sega of America established localized versions and its regional variants.
These publications derive their backstory from the Sonic Bible, an internal document produced by Sega of America during the production of the original Sonic the Hedgehog game. At the time of writing, Sega of America had little to no exposure to any original Japanese fiction relating to Sonic, and the book was an attempt to establish the definitive backstory of Sonic the Hedgehog in non-Japanese regions.
Notable publications that used this backstory include the Sonic the Hedgehog promotional comic, (the first Sonic-related comic published anywhere in the world), the guidebook Stay Sonic, and the French comic series Sonic Adventures. The long-running comic series published by Fleetway Editions, Sonic the Comic, also based its backstory on the early Sonic canon. During its run, however, it also established its own identity separate from the original Sonic Bible, this being to the extent that many features from early Sonic canon are now known much more from their appearances in Sonic the Comic than in any other publication.
Although the early Sonic canon was not used explicitly used as a backstory in any of the American animated Sonic TV series, such as Adventures of Sonic the Hedgehog, Sonic the Hedgehog, Sonic Underground or the Archie Comics series that was based on them, they nevertheless used certain elements that had initially been introduced for the Sonic Bible. The most obvious element was the fact that these series were all set on Planet Mobius, a name that first appeared in the Sonic Bible. Other references include the Warp of Confusion from Adventures of Sonic the Hedgehog (which the Sonic Bible had used as the name of the original Sonic the Hedgehog's Special Stages), along with Princess Sally and the Freedom Fighters of the Sonic the Hedgehog TV series (who were loosely modelled on Sonic's animal friends).
No Japanese media ever followed the backstory established nor adopted the early Sonic canon. As storylines were integrated into the games, the Japanese home-grown backstory (set on an unnamed planet rather than Mobius) became more prominent worldwide, and the elements of early Sonic canon were marginalized. The early Sonic canon was finally retconned away with the release of Sonic Adventure 2, which revealed that Dr. Robotnik's grandfather was named Gerald Robotnik, which contradicted the early Sonic canon backstory that Robotnik had once been called "Doctor Kintobor."
Although each publication gave the backstory its own spin, certain common elements exist in most continuities based on the early Sonic canon, including the following:
- The Sonic the Hedgehog games are set on a planet called Mobius.
- Sonic was an orphan who was raised by his animal friends named Sally Acorn, Porker Lewis, Johnny Lightfoot, Tux, Flicky, Joe Sushi and Chirps.
- Sonic was originally a brown hedgehog, but he became blue after running faster than the speed of sound.
- Dr. Eggman, known consistently in these stories as Dr. Ivo Robotnik, was once a kind scientist named Dr. Ovi Kintobor who was transformed into his current state during an accident involving a rotten egg, the Chaos Emeralds, and a machine called the Retro-Orbital Chaos Compressor (ROCC).
- Prior to this transformation, Doctor Kintobor attempted to use the Chaos Emeralds to rid Mobius of all evil. His attempts were unsuccessful because he could not locate the seventh and final Emerald, the Grey Emerald.
The following publications contain explicit references to elements of the early Sonic canon. Other books by the same publishers are assumed to use the same canon unless otherwise stated.
- Sonic the Hedgehog promotional comic
- Sonic the Hedgehog, published by Archie Comics.
- Stay Sonic, published by Penguin Books under the Fantail imprint
- The Official Sonic the Hedgehog Yearbook (1991), published by Grandreams
- Sonic the Comic, published by Fleetway Editions
- Virgin Books publications:
- Sonic the Story, published by Ladybird Books
- Sonic Adventures, published by Sirène