The Xorda are an aggressive alien race that appeared in Archie Comics' Sonic the Hedgehog series. First appearing in Issue #124, these vindictive beings attempted to destroy the planet Mobius, only to be thwarted by Sonic the Hedgehog.
Biology
The Xorda were a sentient species that had evolved to thrive in aquatic environments. They appeared to be large octopus-like creatures composed mainly of brain matter with a single eye, tubes for expelling gases from their bodies, and many long, writhing tentacles. The Xorda were highly intelligent creatures, telepathic and largely dependent upon technology.
History
Aside from their contact with Mobius, next to nothing is known about Xorda society or history. Thousands of years past, when Mobius was dominated by humans and known as Earth, the Xorda visited the planet on a mission of exploration and attempted to make contact with the human race. Attempts at communication were met only with hostility by the humans who captured and killed the Xorda ambassadors, dissecting the aliens in order to study them.
In response to this barbaric act, the vengeful Xorda bombarded Earth with powerful Gene Bomb weaponry, determined to destroy all life on the planet. The Xorda then left, unaware that some life-forms had survived the bombing and would become mutated by the irradiated genetic material that now saturated the planet's atmosphere. This would lead to the development of the anthropomorphic animals known as Mobians as well as human off-shoots called Overlanders, which would re-populate, re-civilize and re-name the planet in the coming centuries.
Roughly 12,000 years after their first visit to Earth, the Xorda returned and discovered to their outrage that the planet - now known as Mobius - was now populated by new creatures that had evolved from remaining animals and humans left over after their first bombardment. The Xorda refused to allow any trace of humanity to remain and attempted to finish what they had began, launching an attack on the Eggman Empire and against the Overland Nation. Dr. Eggman entered into an alliance with the Knothole Freedom Fighters, requesting that Sonic the Hedgehog use his super-speed to power up his massive robot, Gigabot Prime, which would be powerful enough to destroy the Xorda ship.
Sonic used Gigabot Prime to knock the Xorda ship out of orbit and send it hurtling across space, but as the ship tumbled through the void it deployed the Xorda's ultimate weapon: the Quantum Dial. The Quantum Dial would create a black hole that would completely engulf Mobius and the entire solar system and was protected by a barrier that destroyed any technological device that approached it. Gigabot Prime was dismantled when it flew toward the Dial, and the combined forces of all of Mobius' major powers were unable to get past the Dial's defensive batteries. As the Quantum Dial prepared to fire its quantum wave, all of its defensive weapons were disabled by Knuckles the Echidna when he returned from the afterlife. The Quantum Dial subsequently imploded when Sonic used his super speed to reverse the direction of its internal gears. However, the implosion of the Quantum Dial also resulted in an anomaly which sent Sonic 849,000 light years away to the planet Thoraxia.
Following the Xorda invasion, Sonic was presumed dead and the Eggman Empire waged a full-scale war against the rest of Mobius. With his greatest enemy gone, Dr. Eggman was determined to conquer Mobius once and for all, but Sonic would return home a year later. As for the Xorda, they had learned of their failure to destroy Mobius and were prepared to declare war, but became embroiled in a conflict with another warmongering race known as the Black Arms. The Xorda never made another return to Mobius and were presumed to still be fighting the Black Arms up until the Super Genesis Wave occurred and re-wrote reality, removing the Xorda from existence.