Sometime around Sonic's return from space, A.D.A.M. covertly began operating under the codename of "Anonymous," becoming an enemy to Sonic and Robotnik alike. A.D.A.M. caused the spread of Robotnik's nanites into Jules, Bunnie Rabbot, Nicole, and Tommy Turtle's shell. Although Robotnik discovered his treachery and attempted to delete A.D.A.M., A.D.A.M. managed to download himself into Tommy Turtle and rake over his body.

Once he had done this, A.D.A.M. out into motion his final plan to harness all the Chaos Emeralds in the known universe. He was thwarted in this by Super Sonic, Super Shadow, Turbo Tails, Robotnik and Tommy himself. A.D.A.M. and Tommy were both destroyed.

When Amadeus arrived, he found that Warlord Julian (Who was eventually to become Robotnik) had entered the lab without waiting for him like Julian was supposed to do. Amadeus ended up witnessing someone being roboticized and hearing Julian talk about world domination. Amadeus tried to stop Julian by himself, but was captured and roboticized. As it turned out, Tails was born on this very day. Since it wouldn't look right for Amadeus to not see his son, Julian came up with an excuse of Amadeus being around hazardous materials to cover up Amadeus so that no one realized that Amadeus was a robot when he went to see Tails, who the roboticized Amadeus rejected causing Rosemary to cry herself to sleep.

Shortly after this, Amadeus and Rosemary were both abducted by the alien Bem, and Amadeus was restored to flesh. Although they missed Tails, they lived a relatively comfortable life on Argentium, eventually encountering Sonic when he traveled there. Not long later, though, war broke out between the Xorda and the Black Arms, and the devastation brought Argentium to its knees. Amadeus and Rosemary were saved in the nick of time by Sonic and friends, and Amadeus resumed his position in service to the Court of Acorn, full of new ideas from his long stay on Argentium.

Amy Rose - the young hedgehog with a hopeless crush on Sonic! Sonic could do without her, but once she's got a hug in edgewise, there's no shaking her off!

One of Sonic's biggest fans, Amy tagged along with him to Never Lake when Eggman tried to take control of the Little Planet in Sonic CD. She was kidnapped by Metal Sonic to be the prize in its famous race with Sonic.

After Sonic rescued her, Amy met him a few times in competitions, but mostly shopped around Station Square, where she has an apartment. She didn't do much adventuring, until one day a bird flew into her groceries while she was daydreaming about her adventures with Sonic on the Little Planet. The bird was flying away from Zero, one of Eggman's new E-100 series robots. She helped the bird to hide, and protected it from Zero until meeting Sonic. After getting kidnapped once again, she was rescued on the Egg Carrier not by Sonic, but by a mysterious and unlikely ally. As she continued fighting Zero, she eventually became more independent and decided to win Sonic's respect rather than chasing after him all the time.

Little Amy is more than just an annoyance. She's mastered the Lovely Kiss Attack, a charm move that confuses its receiver into a mindless daze. She has few redeeming hand-to-hand combat qualities, but her Magical Hammer can easily pound a few braincells out of any opponents with just a light swing. It's this colorful, oversized mallet that she used to hold her own in the Sonic Championship fighting tournament. Her "Pico Pico Hammer Attack" also keeps her path clear in Sonic Adventure. Amy also has two small cars that she uses for travel. The Breeze is a small blue car that almost seems to have a mind and face of its own. She's also got a red convertible, which she used in the World Grand Prix. It's lifeless and a little on the slow side, but it comes equipped with an automatic hover engine and a Turbo Boost!

Since then, Amy adapted to life and came to fall head over heels for the local hero, Sonic. She assumed the position of his #1 fan and is ALWAYS on his heels! She has kept her distance out of respect for Sally, but with the current situation of the Sonic/Sally relationship, anythign's possible.

Amy has proven her worth in battle several times and is now officially a full time member of the Freedom Fighters. She has become quite a powerful ally with her Piko-Piko hammer and Tarot card abilities.

Amy Rose entered the comic as Robotnik’s prisoner and nearly left the next issue to become a premature version of the Cybernik, however a reluctant Sonic rescued her with only seconds to spare. She was locked up for claiming to be Sonic’s girlfriend and when she joined the Freedom Fighters she and Sonic were forced to make an agreement.

Self sacrificing and one of the few members of the gang with a cool head Amy became extremely close to Sonic when they were stuck together on the Miracle Planet for a month, even though he spent most of the time hiding from her. When they got back down to Mobius she gradually began to grow and become more independent. She practiced with the crossbow and soon became proficient enough to fend for herself. She became a tutor and mentor to tails, good friend of Tekno the Canary and although perhaps an equal to Sonic, although she liked him too much to ever take any of his glory. When Sonic was stranded in the special zone she became the leader of the freedom fighters but even her cool demeanour was shaken by Shortfuse. After the fall of Robotnik she slowly developed more of a tomboy attitude and changed from the small girl she had originally been to a mature teenager, befriending Tekno. The pair of them travelled the universe with the Eternity Ring, fighting for justice.

The Ancient Walkers were three mystical deities that watched over Mobius and protected it. Although they often appeared together in the form of disembodied tiki heads, they have been seen in the form of dinosaur-like bodies. The Ancient Walkers had a penchant for speaking in riddles and tongues, never revealing their secrets and always a mystery. The only beings known to communicate with them directly on a regular basis were the echidnas Athair and Aurora, as well as the wizard Merlin Prower.

However, Sonic, Knuckles, and Tails have had some limited contact with the Ancient Walkers, at various points in their adventures. It was due to the Ancient Walkers' intervention that Mammoth Mogul has been defeated multiple times, but Mogul eventually took revenge and disrupted the Chaos Force so greatly that the Ancient Walkers were destroyed. Before their death, however, they appointed Merlin, Aurora, and Athair as their successors.

Then, according to legend, a god of the skies came from the heavens, brought back to life part of this civilization, and placed the Master Emerald, along with the land around it, into the sky, forming what we now know as Angel Island. And by no means was this a small amount of land. With over 12 zones, Angel Island is HUGE. It houses all of the traditional animals (minus Picky), as well as a wide variety of interesting areas to explore, none of which are known better than Knuckles the Echidna, the last known remnant of the ancient race, and self-proclaimed guardian of the island, and the Master Emerald.

Though the Master Emerald keeps the island afloat, it has been forced into the ocean before when it served as the crash site for Eggman's Death Egg. The Master Emerald also cannot seem to keep the island up when it is in contact with the 7 Chaos Emeralds...

During one of his trips to the mainland, Knuckles acquired another chaos emerald, bringing the total to two chaos emeralds on the island. The Master Emerald (aka ME) was created as a result of an epic battle against Master Mogul, which resulted in his 12 chaos emeralds being combined with the 2 emeralds already present. More recently, Robotnik shattered the ME (freeing the trapped Mammoth Mogul) and caused the island to fall, but Knuckles recovered most of the pieces to restore the ME and the Floating Island to the skies.

The Island was originally known simply as the Floating Island but it was rechristened "Angel Island" after Angel-La. The Island fell under Robotnik's control and the dingo overlords opressed the Echidnas, who became a shadow of their once-proud society. With help from Knuckles and the other heroes, they have overcome the Dingoes and are now on the mend.

He played no major role in the group for some time except as an annoyance to Evil Sonic. However, because of Evil Sonic's personal vendetta against him, Anti-Antoine and Antoine Prime were switched. For months, nearly everyone believed that Antoine Prime had lost interest in Bunnie and become a cold-hearted soldier, while the truth was that he has been replaced by Anti-Antoine, who had decided to masquerade as the real Antoine in an attempt to sieze power on Mobius Prime. None of the inhabitants of Mobius Prime knew about this until Anti-Antoine violently attempted to take the throne, causing Sonic to realize the truth and execute a reversal of the switch, restoring Anti-Antoine to Anti-Mobius.

Because of Evil Sonic's personal vendetta against Anti-Antoine, Anti-Antoine and Antoine Prime were switched. For months, nearly everyone believed that Antoine Prime had lost interest in Bunnie and become a cold-hearted soldier, while the truth was that he has been replaced. None of the inhabitants of Mobius Prime knew about this until Anti-Antoine violently attempted to take the throne, causing Sonic to realize the truth and execute a reversal of the switch, restoring Antoine Prime to Mobius Prime and reuniting him with Bunnie Rabbot.

After the first defeat of Enerjak, Archy has been like a mentor to Knuckles, but he has kept several secrets. Fire ants live to VERY ripe old ages and Archy is no exception. He trained several previous guardians including Knuckles's own father, Locke. Archimedes knew of Locke as well as the Guardian homebaseat Haven, even though Knux thought them all to be dead. Archy is also a valued member of The Council Of Ants. The Council - which resides in the Lava Reef Zone serve as advisors to the echidna guardians in their time of need.

After Robotnik took over Angel Island, Archimedes was charged by Locke with doing all he could to protect the Master Emerald. This he did. Also, Archimedes hypothesised correctly that Knuckles would regain his chas powers if exposed to the Master Emerald.

The worlds first Benoulli spherical space-colony Ark was built many years ago, housing some of the worlds finest minds who travelled into space to the most advanced research centre of its kind. One of these was Professor Gerald and his granddaughter, Maria. He made contact with the Black Comet and with Black Dooms help created the Ultimate Life Form; Shadow. However, not trusting Black Doom he also began construction of a powerful weapon; the Eclipse Cannon.

Unfortunately due to the Professors work G.U.N. stormed the space colony, killing whoever they couldn’t capture. Maria was among the lists of the dead, a fact that drove Professor Gerald mad, programming the Space Colony to crash into earth. He left the Biolizard, the prototype ultimate life form to make sure this happened and programmed Shadow to take the Chaos Emeralds there.

Shadow realised that his mind had been tampered with and with Sonic stopped it from crashing into the planet. The ARK was saved and when the Black Arms invaded Shadow returned to it to take control of the Eclipse Cannon. With it he opened fire on the Black Comet and destroyed them forever.

Athair told tales of Mobius' ancient past, the coming of the great Chaos Emerald meteor, and also revealed the secret that the "Great Downunda crater" was once the place where The Floating Isle sat before it rose into the sky... how did Athair know all of this? The Ancient Walkers - three mystical diety like beings that come in the form of giant tribal masks. When Tails awoke from his dazed slumber in the crater, he found every trace of Athair gone.

Much later, Athair was invlolved when Mammoth Mogul revealed his plan. After near-destroying Enerjak, Mogul, seeking to absorb the Chaos Emeralds of the Floating Island into himself - turned hyper and became Master Mogul: powered with the enegies of 12 Chaos Emeralds, it took Super Sonic, Hyper Knuckles, Turbo Tails, The Chaotix, The Freedom Fighters, the Echidna Security Team, and The dingoes - and NONE of the them could bring him down. That is, until Athair appeared. With the Ancient Walkers, Athair rescued Sonic, Knuckles, and Tails from dimensional limbo and dropped off the Chaos Syphon - the device used to create Enerjak. It was only with the syphon that the trio got the upper hand to defeat Mogul - but NOT before Athair vanished again...

So what is his relation to Knuckles and the guardians? It wasn't until weeks after the Mogul incident that Knuckles found out. Years ago, Athair himself was a guardian. Father to Sabre, Athair heeded what he called "a beckoning" from the Ancient Walkers. Following his call, he discovered The Forgotten Tribe - a group of Echidnas that decided to not go along with the decision to raise the Island. Simiar to Guardians, The tribe was led by "Mitres" instead. The most recent one had died and Athair had just seemed to enter the picture. Out of sheer heart, Athair renounced the ways of the Guardian to help the poorer shambles that were the Forgotten Tribe find their "Lost City Of Albion", homeland to the echidna race that had vanished centuries ago. Athair took Knuckles to see the Tribe, and on the last night of his mitreship, he vanished mysteriously again. Knuckles - with the help of Rob O' the Hedge, an echidna named Yanar, and Rob's betrothed Mari-An, located the city after more than 600 years of the Tribe looking. Knuckles still wonders to this day what happened to Athair, but had he looked in the sky, he would have seen clouds in the shape of Athair and The Ancient walkers that smiled down upon him...

Bartleby is probably the most important character in Sonic Underground who isn’t part of the main cast, unlike Sonic, Manic and Sonia he refuses to travel around fighting Robotnik but he isn’t part of Robotnik’s evil schemes either. He stands directly in the middle, a close friend of Sonia who would probably quite like to marry her purely for the status in society but until Sonia comes to the throne he hedges his bets and refuses to oppose Robotnik in public. Bartleby has a mutual hatred with Sonic and Manic, and his relationship with Sonia is testing at times, especially as in her absence he continues to flirt with every other eligible woman in Robotropolis. Although he has a decent heart and secretly hates Robotnik, Bartleby does little to help the resistance unless he can get something in return or Sonia forces his hands. If the Queen ever returned Bartleby promises that he would be the first to join her retinue, but until she does he remains squarely neutral with equal contempt for both sides but kept in place by the wealth and money he so dearly loves.

The Black Asteroid was once the biggest gemstone mine on Mobius which somehow ended up in the Special Zone. All that’s left is the ancient tunnel shafts that litter the asteroid around a central platform. When Super Sonic was stuck in the Omni Viewer Chaotix decided to try and seal him away in the Black Asteroid and use a Gravitron Bomb to close of the entrance.

Unfortunately when Super Sonic realised what was going on he had no intention of waiting and instead he started to heat up his surroundings, when the Omni Viewer released him to escape the Black Asteroid became a sort of second sun, heated to millions of degrees, soon to explode. However the scientific group Equinox also discovered that when it exploded it would release an Electromagnetic Pulse, every computer system on the planet would be disabled, hospitals would shut down and aeroplanes would crash, the banking system would fail. Sonic came up with the idea of sending the Black Asteroid to Mobius where the Electromagnetic Pulse would destroy Robotnik’s Empire. The Omni Viewer complied, sent the Black Asteroid to Mobius where it exploded harmlessly, releasing Super Sonic and an Electromagnetic Pulse onto Robotnik.

“600 years ago the folk of Mobius lived in separate tribes, at the time it was ruled over by King Leer a hyena who delighted in torturing the other tribes. In those days the different people were reluctant to help each other but they soon learnt that the Hyenas didn’t care who they overrode. However one rebel was willing to stand up to King Leer! Sonic’s ancestor, Bravehog, leader of the hedgehog tribe. When King Leer sent his Hyenas to the Fox Tribe Bravehog appeared at the last moment and fought off the Hyenas. Unfortuantely the foxes weren’t willing to help Bravehog and fled as more Hyenas arrived and captured him. Soon after King Leer arrived and proposed to shave of his spikes for his disobedience however Bravehog’s final speech to the people was so inspirational that the other nations banded together to help save him. United the Tribes soon fought back, inspired by Bravehog’s battle cry. From that day the people of Mobius Lived together…”

600 years later Sonic retold that very story to a masked man fleeing from badniks who wanted to know where Sonic got his nerve from, Sonic replied that it was “In the blood!” Sonic was rightly proud of his ancestors but the Hyena who unmasked himself couldn't say the same. However Sonic consoled the Hyena, it wasn’t his fault his "ancestors were deadheads".

The first Metallix was built to defeat Sonic by matching his speed and durability. But Sonic managed to beat him thanks to ingenious use of the Time Stones and a lot of luck. Robotnik quickly realised more would be needed, he could defeat Sonic with sheer numbers and quickly commissioned a special plant to be built in the special zone.

They were first noticed by Knuckles and the Chaotix when they rescued the Omni Viewer from them, although not until after the Emperor had created a copy. Not long later the Brotherhood broke into Robotnik's capitol and kidnapped Grimer, going independent from Rrobotnik. Robotnik sent Sonic to deal with them but the hedgehog was too late to stop them travelling to the Miracle Planet with the Alpha Device, intent on recreating the world in their image. Sonic, Amy, Johnny and Porker all headed up the Chain to the Miracle Planet to stop them. After destroying one Metallix through its weak point, the neck, Porker reprogrammed the machine to take Sonic, Amy and Johnny as hostages and then self destruct with the Alpha Device, destroying most of the Metallixes. Porker reprogrammed the Alpha Device and slowly the ground around the device began to return to normal. However as they left Porker noticed the Emperor was still alive, albeit without his flying base and was crawling towards the Alpha device. He ran back down to the Miracle Planet to stop it and then faded from sight as the Miracle Planet disappeared.

The Brootherhood used their copy of the Omni Viewer to rewrite history so there had never been a Doctor Robotnik, but they still existed since it was Grimer who had designed and created them. Sonic and the Chaotix travelled back in time to correct that fault, putting Robotnik back in charge of the planet and returning home. Then the brotherhood turned on Robotnik’s base, explaining the real reason they wanted the dictator dead. He, not Grimer, had been the only one with any sense to put a deactivation code in the Metallixes, in case they ever turned on him. Now he was back he deactivated them and swore that he would never build an intelligent robot again.

When a guardian becomes part of the Brotherhood, he or she graduates from the responsibility of monitoring and protecting Angel Island to responsibility for an entire section of Mobius. Usually, however, they do not intervene in the affairs of other species unless they directly affect Echidna well-being.

Since Robotnik took over Angel island, the brotherhood have been missing except for Locke, who is determined to find out what happened to them.

Spectre - The son of Tobor, Spectre is the wild card of the Brotherhood. Dark and ruthless, he is always trailed by a cloud of smoke, his fur is jet black and his eyes are blood red and his head is covered with a robotic visor...
Thunderhawk - Monitor of the country of Downunda, this purple echidna is the loudmouth complainer of the group. Always ready to put his opinion in when nobody wants it, he's always either getting into an argument with Locke or Spectre.
Sojourner - Thunderhawk is the complainer, Sojourner is the whiner. The father of Janelle-Li, Sojourner doesn't have much going for him and seems to be the guy that would always prefer "the easy way out" rather than all the other hoopla the rest of the Brotherhood goes through.
Sabre - The son of the mystic Athair, Sabre often takes the role of "leader" though he is not. Sabre is the brains of the group and often the peacemaker as well. He is also usually the best in problem solving as well.
Locke - The son of the Sabre and the youngest of The Brotherhood, Locke is the "mistake" guy. Quiet, observant, and always behind a computer screen to monitor his son Knuckles, Locke is not only the mechanics whiz, but he is also the first to defend Knuckles NO MATTER WHAT the situation.

Bunnie Rabbot, with her southern belle accent and sugar-sweet disposition, is not only the strongest of all The Freedom Fighters, but the heart of the group as well. Since being taught some martial arts moves from Princess Sally herself, Bunnie's been able to flatten a door with one kick, split a boulder with a judo chop and "just plain ol' pound some Swatbot be-hind." Bunnie still maintains her perky personality despite squeaking and clanking if her joints aren't regularly oiled.

Bunnie's family comes from the Southern part of Mobius. Armed with a portable roboticizer, Swatbots captured and roboticized many southern Mobians, including Bunnie's parents. Bunnie escaped but was followed and later captured herself. It was there that she was rescued by Sonic and Rotor, but the roboticization process was halfway done, which left one arm and both legs roboticized. She has gone through much emotional pain because of this, yet she has matured into a loyal Freedom Fighter with exceptional strength and determination.

During the final days of Robotnik Prime's reign over Mobius, Bunnie developed feeligns for fellow Freedom Fighter Antoine D'Coolette, and for a very long time they were a couple. However, Bunnie noticed a sudden change in Antoine's attitude and they broke up, leaving Bunnie heartbroken and so desperate that she turned to Sonic for romance. However, when it was revealed that Antoine had actually been replaced by Anti-Antoine, Bunnie was reunited with the real Antoine and they continued from where they left off.

For a long time, the only Chaos Emeralds known to Mobians were the hundreds (perhaps thousands) of Green Chaos Emeralds which existed on Mobius. However, Sonic later encountered Red Chaos Emeralds while he was in space. These had different properties from the Emeralds with which he as familiar. When A.D.A.M. wished to harness all the Chaos Energy in the universe, he summoned all of the emeralds to himself. In addition to the Green and Red Chaos Emeralds, there were five other colors, Blue, Yellow, Gray, Cyan, and Purple Chaos Emeralds. When A.D.A.M. was defeated, these were sealed into the Zone of Silence where their form was changed.

In their new form, there are seven Chaos Emeralds, each in one of the colors of the seven original types. These Emeralds are apparently identical to one another in properties, and are probably slightly different from the original Mobian Chaos Emeralds. The only Chaos Emerald which escaped this reformation was the Master Emerald. The Gray Chaos Emerald is currently in the possession of the Kingdom of Knothole. The other six Chaos Emeralds reside in the Zone of Silence, which has newly been renamed the Special Zone.

Charmy's small size and light weight make him a difficult target, which is compounded by his ability to fly out of any danger and to any altitude. Not only that - BUT his diminutive size makes it easy for him to get into many places unnoticed. Charmy, unlike the other Chaotix, doesn't spin. His unique Buzz Attack, similar to Vector's Power Boost, can tear right through the most powerful of Badniks with relative ease. He also has a unique alternative to the Spin-Dash, the Buzz Dash, which has the same effect but can be done instantly with no charging. His flight range is unlimited, and using Ring Power, this little honey bee is even strong enough to lift his friends into the air with him.

During the Great War, Colin and several other Overlanders tired of the constant wars and strife, and decided to leave Mobius for a better life in space. So Colin, his first wife and their followers boarded several spaceships and left for parts unknown for nearly a generation. Along the way, the encountered many different worlds, and came in contact with aliens such as the Xorda - who, through Colin's Overlanders, learned that they had not wiped out the people of Earth.

When Colin and his group returned to Mobius after many years abroad, Colin returned with his new mother-in-law, Agnes, and his daughter by a second marriage, Hope. When Robotnik - rather, the Robotnik formerly known as Robo-Robotnik - learned of this, he decided to run with it. So, he convinced the arriving Overlanders that Sonic was an enemy (no thanks to Monkey Khan ruining Sonic's attempt to warn the group against trusting Robotnik) and that going to his city would provide protection.

Unknown to the group, however, the city was filled with poisons and toxins that would eventually kill them all through exposure. Also unknown to the group was the fact that they were helping Robotnik seal their fates - they helped him perfect his robotic arm so he could perform robotization just by his touch!

It is this 'touch of death' which took Colin's humanity, turning him into a robotic statue alongside Nate Morgan, Lady Agnes and many others that would follow.

The first four victims of the robotic touch - Cheddarmund, Colin, Nate Morgan and Lady Agnes - were also victims of a nuclear explosion that obliterated Robotropolis. It is highly doubtful they survived.