Mobius

Mobius is the planet that the Sonic the Hedgehog characters are from in SatAM, Adventures of Sonic the Hedgehog, Sonic Underground, and the comics. Mostly anthropomorphs live there. Note that while originally, some of the American storylines also had Sonic games set on Mobius, the original Japanese manuals have always had Sonic living on Earth, and since post-Sonic Adventure games have followed the Japanese storylines in all regions, it's safe to say Sonic has always lived on Earth in the games.

Adventures of Sonic the Hedgehog
The animated series Adventures of Sonic the Hedgehog provided one of the earliest versions of the planet Mobius. The overall look of the planet was cartoony and the population ranged from the series' standard humans and anthropomorphic animals to sausage people and other oddities.

In this continuity, as in the Japanese version, the place is completely free, with Dr. Ivo Robotnik just trying time and again to take it over (and usually failing miserably).

Sonic the Comic
Sonic the Comic, a UK-based comic published by Fleetway Editions, and certain other books, provided a Mobius backdrop far more consistent with the style of the first few games. Once again, the inhabitants of the planet were anthropomorphic animals. Sonic the Comic notably divided the planet up into "zones", each with its own distinctive landscape and climate, in a similar manner to the early games. Key Zones were the Emerald Hill Zone, home of Sonic and a frequent target for Robotnik; the Metropolis Zone, here a capital city (with its skyline looking much like Mega-City One) for the planet and Robotnik's base of operations, via his Citadel Robotnik building; Casino Night Zone, given residential areas and the haunt of recurring gangster villain Max Gamble; Chemical Plant Zone, setting for the Tails' 'Zonerunner' stories; and Mushroom Hill Zone on the Floating Island, where the Emerald Hill Folk hid to escape Robotnik. Original Zones, like the Stone Tower Zone and the upper-class Eldorado Zone, were also created.

In this version, Robotnik eventually took over the planet and ruled as dictator for years, using his subjects as slaves and forcibly turning them into Badniks. He was eventually overthrown and went into hiding, however. A recurring theme through the latter half of the comic's run was that there had once been a war on Mobius between an ancient echidna race (of which Knuckles is one of the last survivors) and the Drakon Empire. The Chaos Emeralds (important in this continuity, as in the games) were a product of that ancient war, and both the Aquatic Ruin Zone and Flickies' Island were old Drakon outposts.

In one issue of the comic, Amy Rose and her friend Tekno travelled to the dawn of life on Mobius, here shown to be caused by a team of scientific dinosaurs in spacesuits who worked for what was hinted to be God.

Mobius was established as an entirely separate world from Earth. In an early Sonic's World strip, the Kintobor Computer claimed that Mobius was in a small galaxy that was "117,63222 light years from Earth", in a parallel dimension, in a different time zone and the whole region is made up of dark matter. Despite this, later stories revealed that travel between the two worlds was possible. Amy and Tekno travelled to the planet Earth several times. On the first occasion, they were accidentally teleported into space and subsequently arrived on Earth by spaceship where they were mistaken for aliens. They later returned to Earth on their trips through the Ring of Eternity, and as a result of this story, rogue British military forces led by Colonel Granite subsequently invaded Mobius before being hurled out, seemingly by nature itself. An even later story showed that, due to their highly similar ecosystems, Earth & Mobius were twin planets.

In addition to Earth, Mobius frequently interacted with other dimensions, most notably the Special Zone, but also including Tantaragor and the Shadow Dimension, among others. The Ring of Eternity, claiming to be the spirit of Planet Mobius itself, revealed that Mobius was an "important centre-point between dimensions".

The subsequent fusing of the energies of Mobius with the enlarged sub-atomic world of Shanazar caused portals to open to various worlds and dimensions on Mobius, including various points in time in Earth's history. The comic ceased its run after adapting Sonic Adventure, though judging by the way they dealt with the events of that game, it is unlikely the writers would have done anything to change this view of the planet.

During a brief period when Robotnik became a god thanks to the Chaos Emeralds, he altered history so that Sonic was never born. The result was a rather horrific, dystopian world: Porker Lewis was a servant of Robotnik, Amy Rose and Johnny Lightfoot (Robotnik Reigns Supreme) were frightened civilians, Tails was dead, and the Emerald Hill Zone was a metal wasteland.

SatAM
Although it was never mentioned in the SatAM show itself, Season 2 head writer Ben Hurst mentioned that he had intended for later seasons to establish Mobius as a future Earth but the series was canceled before such plans would be solidified. The society of SatAM's Mobius consists of anthropomorphic animals called Mobians, ruled by a dictator known as Dr. Robotnik (formerly called Julian) who aims to replace Mobian life with robots via roboticization.

Archie Comics
In the Archie Comics version of Sonic, the writers eventually revealed a similar "future Earth" idea to that intended for SatAM, presumably as a result of the Sega of Japan's decision to do away with Mobius and present it as Earth. Mobians were revealed to be by-products of a genetic bomb dropped many millennia ago by an alien race known as the Xorda. This bomb apparently caused some animals to incorporate a great amount of human DNA. The same bomb also created Overlanders (see below). Contrary to this "Mobius-is-Earth" retcon, earlier comics had stated that Mobius exists in an entirely different universe from our own that can be reached through the Cosmic Interstate, an intergalactic road that connects different universes and realities across time and space. A possible way to rationalize this is to state that the time between the various realities in Sonic is not always in sync. Though, the comics appear to conflict, between Mobius-is-earth or another dimension, you can combine both ideas into one. Mobius IS in another dimension and IS also a future Earth of this particular dimension. In this dimension, Earth had the aforementioned cataclysm and then evolved into Mobius.

Overlanders and humans in Archie
Attempting to reconcile the presence of the obviously human Dr. Robotnik with a planet occupied mostly by Mobians, the Archie writers created the concept of Overlanders, four-fingered humanoids in constant conflict with Mobians. The Overlanders and Mobians famously fought in a Great War, during which the traitor Julian Kintobor helped the Mobians and gained the king's trust. When Mobius was revealed to be Earth, the Overlanders were explained as descendants of human beings who evolved and overcame the Xorda's genetic bomb.

After their defeat in the Great War, a group of overlanders traveled to space seeking out a better life though their journey would eventually take them back to Mobius though not before having a chance encounter with the Xorda which would serve as the cause for the alien's return.

In addition to Overlanders, Mobius has a smaller population of somewhat friendlier humans, who are identical to modern-day human beings who do not share the feelings of racism towards Mobians that seem common to the Overlanders. They survived the Xorda bomb unharmed as they were on board a passenger jet in mid-flight during the attack and crash landed beside a giant mountainous cavern in which would eventually become the human built-city of Station Square. These humans were rediscovered during the time at which the comic's adaptation of Sonic Adventure takes place. Overlanders and humans, despite their minor differences, now occupy a common home in Station Square though as can be pointed out through several appearances in events that proceed the overlander retreat to space, it would appear that the presence of Overlanders on Mobius is not limited to just Station Square. The United Federation which Station square founded is currently allied with free Mobians to fight the Eggman Empire.

Prehistoric
Approximately 12,000 years ago, during the 21st century of the "old world" when Mobius was still known as "Earth", an alien race known as the Xorda came to the planet to offer an alliance to its human population. However, the emissary they dispatched was captured, studied and subsequently dissected by a group of scientists led by Ivan Kintobor, a leading scientist at the time. Ivan had hoped to use the captured alien and its technology to produce the robot Isaac as well as numerous other creations. His methods however proved antagonistic towards the Xorda. In retaliation, the aliens bombarded the planet with Gene Bombs with the intention of exterminating all life on the planet. The bombs had an unforeseen side effect however. The human population underwent a de-evolution, forming the four-fingered Overlanders seen on Mobius today, while the rest of the animal kingdom experienced a rapid evolution, forming modern-day Mobians. (StH: #124, #148)

Early History
Approximately 10,000 years ago, the planet suffered a massive environmental cataclysm. The Gene Bombs were supposed to preserve Earth's environment as it was when it was attacked. However, their interaction with the planet caused massive volcanic reactions, earth quakes, and massive storms, hurling billions of tons of ash and dirt into the air. This is what is chronicled as the First Day of Fury in Echidna theology. (StH: #148)
 * How the echidnas would have records of this time is unknown, as Mobians were still in very primitive stages or not around at all yet. It is possible they learned of this event from geographical remnants of the events, or they located records of it left over from the destroyed earth's population.

Shortly after this cataclysm, the event known as the Coming of the Chaos Emeralds (which lead to the extinction of the Mobosaurs) occurred - a direct result of the Gene Bombs' radiation blending with beryl deposits deep within the planet's surface. This gave birth to the omnipotent beings known as the Ancient Walkers and provided immortality to Mammoth Mogul, when one of the descending Chaos Emeralds embedded itself in his chest. (StH: #148, TMS: #3, SMM)
 * The origin of the Chaos Emeralds has been brought into question given that Isaac was revealed to have corrupted data. However, given the robot's accurate recollection of other known events, his history of the Chaos Emeralds is considered canon until directly proven false in the comics.

The Days of Fury continued to affect Mobius for thousands of years, right up to modern day. The Echidna Tomes describe them as "natures way of adjusting to environmental changes it undergoes over a certain duration" according to Athair. Prior to the Day of Fury which happened in the year 1998 (technically 3235), Athair stated the last recorded Day of Fury happened some "twelve hundred years ago". (KtE: #12)

Approximately 9,700 years ago, the Echidnas were already well developed in their colony of Albion. The Albion Knights of Aurora found themselves defending the planet against the wizard caste known as the Order of Ixis, which was bent on world domination and was subservient to their founder Mammoth Mogul. Despite the Order's incredible powers, the Albion Knights successfully defeated Mogul during the Forgotten War, effectively wiping out all of the Order of Ixis. However, Mogul and three members, Agunus, Nusgau, and Suguna, survived the Forgotten War. The latter three wizards eventually merged to form the individual wizard Ixis Naugus thousands of years later. It was also during the Forgotten War that monstrous creatures of various species, collectively known as Mutates, began to appear across the planet, though in limited numbers. (StH: #66, #67, #163)
 * The 300 year period between the Coming of the Chaos Emeralds and the Forgotten War is based off Mammoth Mogul's look when he was 300 years old, depicted in the Mecha Madness special, due to him having the same look during the Forgotten War depicted in StH: #163. This is only a rough estimate.

Developing Societies
Approximately 1,000 years ago, Dave, an Echidna from Albion, ventured out into space, exploring Saturn and its moon Europa on the Monolith. (KtE: #12, #30)

Approximately 600 years ago, a White Comet hurling towards Echidnaopolis in the continent of Downunda was discovered by the Echidna scientists Jordann and Kayla-La. Using their knowledge of the Chaos Emeralds, the two scientists managed to use the Chaos Emeralds' powers to lift their city into the sky, after the Fire Ants dug underneath the city to separate it from the continent — thus creating the Floating Island. (StH: #34)

Meanwhile, the other Mobians learned from the Echidnas on how to structure themselves into societies. One Mobian, Alexander, decided to pool the various groups resources and knowledge together to form a single society. While the Overlanders proved too violent in nature to be included, and the Echidnas chose to exclude themselves from joining the group, the other Mobians pulled together and created Mobotropolis - the first multicultural city on the planet. (StH: #71)

Modern History
Approximately 21 years ago (1989 (technically 3220)):
 * The Great War between the Overlanders and the Kingdom of Acorn begins. (StH: #73, #112)
 * Sonic the Hedgehog and other future members of the Knothole Freedom Fighters are born. (StH: #112)

Approximately 20 years ago (1990 (technically 3221)):
 * Mobotropolis is heavily damaged by mortar shellings from Overlander forces. (StH: #76)
 * Queen Alicia and Prince Elias' air craft is shot down while flying to the neutral territory of Angel Island, with all hands presumed dead. (StH: #64)
 * Julian Kintobor is rescued by the brothers Jules and Sir Charles Hedgehog in the Badlands. (StH: #74)

Approximately 16 years ago (1994 (technically 3225)):
 * The Great War ends, with the Mobians having achieved victory. (StH: #78)
 * Miles "Tails" Prower is born. (StH: #112, SSS: #9)
 * Julian Kintobor (who renamed himself Dr. Ivo Robotnik) launches a full scale coup d'état, taking over Mobotropolis. (StH: #43, SSS: #9)

Approximately 6 years ago (2004 (technically 3235)):
 * Maximillian Acorn is returned from his exile in the Zone of Silence and later resumes his role as king. (StH: #41, SSS: #4)
 * Dr. Ivo Robotnik dies after his nephew Snively changes the Ultimate Annihilator to target only his DNA structure. (StH: #50, #72)
 * Freedom Fighter groups regain control over Mobotropolis and a brief time of peace ensues. (SSS: #2)
 * Ixis Naugus escapes from the Zone of Silence and attempts to take over the kingdom, but is forced to flee (StH: #53)
 * Enerjak's attack on Echidnaopolis fails after Mammoth Mogul steals his power with the Sword of Acorns. (KtE: #9)
 * Master Mogul nearly enslaves all of Mobius until he is defeated by Super Sonic, Hyper Knuckles, Turbo Tails and Athair. (StH: #56)
 * Ixis Naugus, who enslaved King Max's body, nearly starts a civil war between Robians and Mobians, but his plot fails when he is discovered. (SSS: #4)

Approximately 5 years ago (2005 (technically 3236)):
 * The most recent Day of Fury takes place, nearly wiping out the Lost Tribe of Echidnas. (KtE: #10, #11)
 * The Lost Tribe reunites with Albion, after hundreds of years searching for their homeland. (KtE: #12)
 * Sonic and Tails manage to once again imprison Ixis Naugus in the Zone of Silence, with Nate Morgan's help. (StH: #66)
 * Robo-Robotnik manages to retake Mobotropolis. (StH: #75, #76)
 * The Kingdom of Knothole is officially formed to act as a haven for those opposed to Robo-Robotnik's tyranny. (StH: #78)
 * The Xorda attack Mobius but are repelled. Sonic is transported to another part of the galaxy and presumed dead. (StH: #125)
 * The Eggman Empire is officially formed. (StH: #130)
 * Dr. Eggman formally declares war on the Kingdom of Knothole and the United Federation. (StH: #130)
 * Albion is completly destroyed by the Eggman Empire after Dr. Finitevus sabotages its defenses. (StH: #182)
 * Angel Island falls to the forces of the Eggman Empire and the Dingo Regime. (StH: #130, #138)

Approximately 4 Years ago (2006 (technically 3237)):
 * Sonic the Hedgehog returns from outer space and helps to prevent the Eggman Empire from launching nuclear missiles. (StH: #130, #131, #132, #133)
 * Golden Hive Colony is obliterated by the Eggman Empire with almost no survivors. (StH: #138)
 * The Ancient Walkers are killed when the dimensional barriers are breached. (StH: #162)
 * The Great Harmony is achieved by the "Chosen One", who subsequently sent all the Chaos Emeralds into the Zone of Silence. (StH: #169)
 * The Eggman Empire destroys Knothole Village via aerial bombardment with the Egg Fleet. (StH: #175)
 * The citizens of the Kingdom of Acorn are rescued and transported to New Mobotropolis. (StH: #176, #177)
 * Angel Island is liberated of its Dingo oppressors by Enerjak. (StH: #181)
 * The majority of Echidnas, (having been reduced to 10% of their former population) are relocated to Albion's former site by Enerjak. (StH: #181)
 * New Megaopolis is destroyed by Enerjak. Some surviving Echidnas, under Lien-Da, ally with Dr. Eggman. (StH: #182, #183, #184)
 * After Moebius is conquered by Scourge, he and the Suppression Squad successfully invade Mobius Prime. (StH: #189)
 * The Suppression Squad rebel against Scourge and he is defeated and imprisoned in the No Zone. (StH: #193, #194, #196, #197)
 * The Freedom Fighters launch their final attack against the Eggman Empire's ruined capital city. (StH: #198, #199)
 * Dr. Eggman loses his sanity after his final fight with Sonic, ending the Second Robotnik War. (StH: #200)
 * The Eggman Empire is usurped by the Iron Dominion. (StH: #200)

Continents/Island

 * Angel Island (floating)
 * Big Kahuna Island
 * Devil's Island Gulag
 * Downunda
 * Flicky Island
 * Mainland
 * Skoal Island
 * Southern Tundra
 * Walrus Island

Main Political Factions

 * Albion Government (destroyed)
 * Dark Legion (reduced to military troops for the Eggman Empire; renamed the Dark Egg Legion.)
 * Eggman Empire
 * Dingo Regime
 * Kingdom of Mercia
 * Republic of Acorn
 * Kingdom of Acorn (formerly)
 * Kingdom of Knothole (formerly)
 * Theocracy of Angel Island (destroyed)
 * United Federation

Mobian Cities & Territories

 * Albion (destroyed; rebuilding)
 * Cavem Canus (destroyed)
 * Dragon Kingdom
 * Echidnaopolis (destroyed)
 * Feral Forest
 * Furville
 * Golden Hive Colony (destroyed)
 * Kingdom of Leonus
 * Knothole Village (destroyed)
 * Mercia (aka "Snottingham")
 * Leung Kar (destroyed)
 * Leung West (destroyed)
 * Mobotropolis / Robotropolis (destroyed)
 * Mysterious Cat Country
 * Nekronopolis (erased)
 * New Mobotropolis
 * Nerb Kingdom
 * Sand Blast City
 * Stormtop Village
 * Vesuvio
 * West Robotropolis
 * Western Continent Village

Overlander/Human Cities & Territories

 * Overland
 * Megapolis
 * Mega Central


 * United Federation
 * Station Square
 * Soleanna


 * Eggman Empire
 * New Megaopolis (in ruins; only the Eggdome remains operational)
 * Old Megaopolis (remains of the destroyed New York city)

Other

 * Badlands
 * Canyons
 * Deerwood Forest
 * Emerald Sea
 * Great Canyon
 * Great Forest
 * Great Rainforest
 * Land of a Million Lights
 * Lethal Radioactive Zone
 * Mobian Ocean

Sonic Underground
Like in SatAm, Mobius was conquered by Robotnik who polluted and Roboticised most of the planet. Unlike SatAm, most of the Mobian population remained in the flesh (as only those breaking Robotnik's laws were Roboticised). Mobius possesses a large aristocracy, who - outside of taxes - are largely untouched by Robotnik's reign; the vast majority of the population are lower-classes who live in slums & squalor, fearful of being arrested at any time. While the majority of the planet's population is once again anthropomorphic animals, they appear far more alien and are not easily recognizable as Earth animals.

Trivia

 * In the Sonic X TV series it is revealed that many residents and Eggman were brought to Earth during a Chaos Control. They all lived on a different planet but no name is revealed in the series. It can be possible that this planet is Mobius.
 * Mobius is an American concept.
 * Mobius' landmasses are similar in shape to Earth's, but are fragmented.
 * It is most likely that the video game series, all the television series, both comic series, and manga are all part of the multiverse.
 * There's a place in Adventure Quest Worlds called Mobius.
 * Backing up the theory on Mobius being a alternate dimension version of Earth, Geoffrey St. John mentions South America once, and a author's note says "Mobius South America."