Overlanders are slightly-mutated descendants of humans on Mobius. They were a by-product of the Xorda's Gene Bombs, which led to the mutation of the planet's inhabitants. They tend to be aggressive in nature and have strong feelings of xenophobia towards their Mobian counterparts. While most of the population is aggressive, there are a few Overlanders who are neutral or even friendly towards the Mobians, such as the notorious scientist Nate Morgan.
Prior to becoming Mobius, the planet Earth's dominant species was Homo sapiens (Human beings). During Earth's 21st century, the scientist Ivan Kintobor provoked the alien species known as the Xorda by capturing their emissary and dissecting it. As a result, the Xorda bombarded the planet with Gene Bombs, which were supposed to wipe out the human race and maintain the rest of the planet's environment as it was at the time. However, the Gene Bombs instead devolved the human population, creating Overlanders.
Early History and Development
Some time after the Xorda attack, the Overlanders were still a barbaric species. The Mobian Alexander attempted to integrate them into his all-species society of Mobotropolis, but their aggressive tendencies made it too dangerous.
Unlike their Mobian counterparts, who wished to preserve the environment and therefore remained locked in the medieval age for centuries, the Overlanders hit the industrial age and later the atomic age, developing their capital city of Megapolis in the North-Western hemisphere.
War with the Mobians
Between 3220 and 3225, the Overlanders and the Mobians fought the Great War. While the Overlanders were initially defeating their medieval Mobian foes with relative ease, the tide turned when the Overlander scientist Julian Kintobor joined the Mobians and provided them with tactical information, battle strategies and technology. The Great War ultimately and abruptly ended after a sword duel between King Max and the Overlander's leader, the Overlord. An agreement was made by each side that they would surrender should they lose. When King Max defeated the Overlord, he honored his word, surrendering.
Trek Through the Stars
Filled with shame and guilt over their unexplainable loss, most of the Overlanders of Megapolis, led by Julian's brother Colin Kintobor, created two spaceships and fled the planet in search of their own world (this ultimately saved them, as Dr. Robotnik sent legions of SWATbots to conquer the city after he seized power in Mobotropolis). After nearly 11 years of searching, they were unable to locate a hospitable world, and were forced to return to Mobius.
Some Overlanders remained on Mobius, residing in Mega Central, unaware that Julian Kintobor was the evil Dr. Robotnik.
Betrayal and Move
Upon returning to Mobius, the Overlanders found themselves welcomed to the city of Robotropolis by Dr. Eggman, an alternative-dimensional version of the now-deceased Julian Kintobor (aka Dr. Robotnik). Unbeknownst to them, Robotropolis was filled with deadly radioactive poison, which Eggman was immune to due to his robotic body. Eggman planned to keep the Overlanders ignorant of this until they were forced to undergo roboticization in order to become cured. However, the citizens of Knothole became aware of the deadly radiation and warned the Overlanders, who decided to leave the city before it was too late.
Shortly after this, the Mobians relocated the surviving Overlanders to the human city of Station Square, as the physical and cultural differences between them would make it impossible to share Knothole with them. Since then, the Overlanders were cured of their radiation poisoning. The Overlanders had not shown any form of xenophobia towards the humans, maybe due to respect for them; for inviting them into their society and not noticing their differences.
Overlanders are most commonly confused as humans due to their physical similarities. However, the two species have many differences, both physically and mentally. Unlike humans, who are generally friendly and accepting of Mobians, Overlanders usually hold grudges, and in some cases feelings of outright speciesism, towards Mobians. This is partially due to the Great War, though the Overlanders' distrust and dislike of Mobians far predates this war. There are a few Overlanders who don't hate Mobians in any way, which include Nate Morgan, Maria Robotnik, and Hope Kintobor.
Overlanders, particularly those in government or military careers (including the sciences) frequently sport an all-grey body suit. Overlander troops (also known as SWATbots) were typically seen wearing this attire during the Great War. Julian Kintobor was wearing one during his escape through the Badlands, and Colin continued to wear one throughout and long after the Great War.
Overlanders do not share the Mobians' consideration for the environment. While the Kingdom of Acorn deliberately remained in a pre-industrial state to preserve the planet's environment and nature, the Overlanders pursued the use of fossil fuels, resulting in massive pollution in their cities.
Unlike their human counterparts, Overlanders only have four fingers and toes, while humans have five. Doctor Eggman, Snively, Gerald Robotnik, Maria Robotnik, Hope Kintobor, and Iron Queen are the only six Overlanders to have five fingers and toes instead of four.