Knuckles the Echidna


 * "Knuckles" redirects here. For other usages of the term, see Knuckles (disambiguation).

"I'll probably be on this floating island forever, guarding the Master Emerald again. I may not know the whole story behind this, but perhaps it's better that way."

- Knuckles the Echidna, Sonic Adventure

Knuckles the Echidna (ナックルズ・ザ・エキドゥナ) is a fictional, anthropomorphic 16-year-old red echidna from the Sonic the Hedgehog series. He is the latest guardian of the Master Emerald, a powerful ancient relic which is his solemn duty to protect from anyone who wants to abuse it or its usage, and the last member of the echidna race on Earth. His dominant traits are his superhuman strength, and the two spike-like knuckles on each of his hands, from which his name is derived from, which he can use to dig with and climb up walls with ease. He can also trap the wind under his dreadlocks to glide through the air.

A loner by nature, Knuckles is independent, headstrong and serious, yet gullible and short-tempered to a fault. He is fully devoted to his duty, spending most of his time on Angel Island protecting the Master Emerald, and rarely cares for anything else. When his friends and others are in need of his help, however, Knuckles can always be relied on being willing to leave his post and prove himself as a true and good-hearted hero. He is also one of Sonic's oldest friends and rivals.

According to official Sonic Team polls, Knuckles is the fourth most popular character in the series, behind Tails, Shadow and Sonic.

Concept and creation
Knuckles was originally created and designed by Takashi Thomas Yuda. During the conception of Sonic the Hedgehog 3, the development team wanted to create a new rival for Sonic. The final design of Knuckles was the result of dozens of possible designs inspired by numerous different animals. The emphasis of the character was to break walls. Knuckles's shoes are based on the colors of the Jamaican flag, and his appearance is overall Jamaican. In fact, he was originally meant to speak with a Jamaican accent.

Early Life
Knuckles was born and raised on Angel Island. He is the last surviving member of the Knuckles Clan, a long-lost tribe of echidnas, which were devoted to protecting the Master Emerald after Pachacamac incurred the wrath of Perfect Chaos who nearly completely wiped out the Knuckles Clan 4000 years ago.

Despite his peoples' colorful history, however, Knuckles's own past was a mystery to him; he did not know how he came to be, nor what other reasons he had for existing, and he believed himself to be the last of his kind entirely. The only thing Knuckles knew about himself was that for as long as he could remember, he had been living on Angel Island, protecting the Master Emerald. He did not know why he was compelled to fulfilling this task, only that it was his sworn duty and fate to protect the Master Emerald from anyone who wanted to abuse its power. As far as Knuckles knew, this was his purpose in life, and he was content with that.

Having his innate oath in mind, Knuckles spent much of life close to the Master Emerald's shrine, steadfastly protecting the Master Emerald from any kinds of threat, while having little to no contact with the outside world. Over time, Knuckles became friends with all the animals and the nature itself on Angel Island.

Sonic the Hedgehog 3
In Sonic the Hedgehog 3, Knuckles was on his usual patrol of the island's pillar, watching over the Master Emerald and the seven Chaos Emeralds. Just as he was making sure that the Chaos Emeralds were in place, however, the Chaos Emerald before his eye began to float as tremors started to occur. Confused at this unique phenomenon on his island, Knuckles witnessed the Chaos Emeralds starting to vibrate violently as the tremors grew worse. When the tremors reached their climax, Knuckles heard an ear-piercing crash just as a brilliant flash filled his vision. Then, without warning, Knuckles was thrown out of the altar and fell unconscious.

When Knuckles later came to, he discovered that he was outside the alter, only to see that the altar itself had been partially destroyed. He flew back to the altar, where he discovered that the Chaos Emeralds had disappeared. Shocked and in a daze, Knuckles left the altar and quickly began traversing the rest of the island. Gazing into the horizon, Knuckles saw the Death Egg, which had crash-landed on Angel Island, with its impact having pushed the island into the sea and caused the previous tremor. Seeing the Death Egg made Knuckles recall a prophecy depicted on murals in the Hidden Palace Zone that said that a dragon would bring disaster to the island. Recognizing the Death Egg as that dragon, Knuckles feared that the prophecy had come true.

Over the next few days, Knuckles patrolled the island while investigating the altar, hoping to find the Chaos Emeralds, but could not find any trace. Knuckles however, refused to give up and continued to investigate the island. Eventually, Knuckles came across Dr. Ivo Robotnik in the woods during his search. The doctor introduced himself as a scientist conducting research on the Death Egg to prevent disaster, before telling that two people, named Sonic and Tails, were out to steal the Master Emerald. Due to his seclusion, Knuckles believed Robotnik and made it his goal to stop Sonic and Tails while keeping them from getting to Robotnik, not realizing that he was being used by Robotnik to keep Sonic and Tails at bay while he rebuilt the Death Egg.

At the time Sonic and Tails finally approached Angel Island, Knuckles was ready to face them. When Sonic arrived on the island as Super Sonic, Knuckles launched an ambush on Super Sonic, pulling a cheat shot on him that forced the Chaos Emeralds out of him. With Sonic in disarray, Knuckles took the Chaos Emeralds, before grinning at the hedgehog, and made his escape. With the Chaos Emeralds in his possession, Knuckles hid them away across the island, before turning his attention to his various traps that was meant to deal with Sonic and Tails.

As Sonic and Tails continued to travel across Angel Island, Knuckles attempted on several occasions to stop the duo. After Sonic and Tails had defeated the Flame Mobile, Knuckles appeared and destroyed a bridge that send Sonic and Tails plummeting into the Hydrocity Zone. Here, Knuckles appeared again later, where he destroyed another bridge that Sonic and Tails stood on, sending them deeper into the city. When Sonic and Tails later made it through Carnival Night Zone, Knuckles appeared before the duo and used a switch to turn off the lights and flood the area with water, before escaping. Later, at Launch Base Zone, Knuckles tried to get rid of Sonic and Tails by destroying the tower they were in with a bomb, but was unsuccessful. When Sonic later tried to use the Egg Mobile to board Robotnik's rocket ship, Knuckles kept Sonic from getting anywhere near it. However, the tremors from the rockets caused Knuckles to trip and fall, allowing Sonic to pass through.

Sonic & Knuckles
In Sonic & Knuckles, after the Death Egg crash-landed on Angel Island again, Knuckles returned to the Hidden Palace Zone. After having finished his errands there, Knuckles used a Giant Ring to get to a hidden room in the Mushroom Hill Zone. After securing the hidden room (not aware Sonic and Tails were watching), Knuckles disappeared into the forest.

Seeing that Sonic and Tails were still exploring the island, Knuckles continued in his endeavors to stop the two of them. When Knuckles later encountered Sonic and Tails in the Mushroom Hill Zone, Knuckles activated a powerful wind that blew Sonic and Tails into another part of the forest. Later, when Sonic and Tails were going through Lava Reef Zone, Knuckles used a large boulder to push them deeper into the volcano.

Following his boulder trap, Knuckles found Sonic and Tails arriving in the Hidden Palace Zone. Upon meeting Sonic there, Knuckles made his final stance against the intruders and fought Sonic, but was defeated. After his defeat, Knuckles heard an explosion at the shrine and went to check the Master Emerald. There, Robotnik's betrayal was revealed to Knuckles very bluntly, as he saw Robotnik had broken into chamber and was stealing the Master Emerald to power the Death Egg. Realizing he had been tricked, Knuckles furiously attacked Robotnik. When he tried to get the Master Emerald back, however, Knuckles was electrocuted, and the mad scientist escaped. Understanding that they were on his side, Knuckles guided Sonic and Tails to a hidden Warp Point to the Sky Sanctuary Zone from where they could board the Death Egg.

Once arriving in the sanctuary, the trio witnessed the successful relaunch of the Death Egg. Knuckles, however, had become too exhausted from the previous two struggles to go on. The only thing the echidna could do now was to lead Sonic and Tails on their way, and then wait for them to bring the Master Emerald back. Fortunately, Sonic and Tails soon returned with the Master Emerald and gave it back to Knuckles. With the Master Emerald secured and Angel Island returning to the sky where it belonged, Knuckles watched on contently as Sonic and Tails left the island in the Tornado.

Unfortunately for Knuckles, the newfound peace came to a hault when one of the EggRobos, under orders from Robotnik to eliminate Knuckles, went to attack the echidna. While he was relaxing in the Mushroom Hill Zone, Knuckles was suddenly ambushed when EggRobo dropped a bomb in front of him. Though luck or toughness, Knuckles survived the explosion and saw his attacker. Enraged, the wild echidna set off to defeat EggRobo.

After having cased the robot across his island, Knuckles followed it to Sky Sanctuary Zone. Once arriving there, however, Knuckles was ambushed by EggRobo, who grabbed Knuckles with his Egg Mobile. Knuckles was then brough before Mecha Sonic, who had stolen the Master Emerald for its own ends, causing Angel Island to wobble in the sky and threating to fall down completely. Before Mecha Sonic could land the killing blow on Knuckles, the echidna escaped the Egg Mobile, resulting in EggRobo's destruction, and he began his showdown with Mecha Sonic. When Mecha Sonic seemed defeated, the robot played its triumph card by harnessing the Master Emerald's power to become Super Mecha Sonic. Despite his opponent's overwhelming power, Knuckles managed to destroy Mecha Sonic by attacking the robot during its recharge cycles, though its defeat caused their battle ground to crumble.

Fortunately, Knuckles and the Master Emerald were rescued from their fall when Sonic arrived in the Tornado and caught Knuckles holding the Master Emerald on the plane. Thanking Sonic for his help, the two of them returned to Angel Island where they brought the Master Emerald back into place. Having saved Angel Island again, Knuckles and Sonic departed ways once more.

Sonic Triple Trouble
In Sonic Triple Trouble, Knuckles was approached by Dr. Robotnik once more, and was duped into believing that Sonic and Tails were out to steal the Chaos Emeralds, not realizing he was being used to gather the Emeralds for Robotnik after the doctor had lost them following a weapon test accident, and as well to deal with Sonic. Regardless, Knuckles resolved to keep the Chaos Emeralds away from Sonic and Tails.

Acting in good time, Knuckles managed to beat Sonic and Tails to it by finding the five lost Chaos Emeralds first, which were then hid away in the Special Stages. When Knuckles later found Sonic and Tails as the duo was searching for information on the emeralds, he appeared before them and blocked their path, and told Sonic spitefully that he would never get his hands on the Chaos Emeralds, before making his escape.

After their encounter, Knuckles tried on several occasions to hinder Sonic and Tails's quest to retrieve the Chaos Emeralds. In Great Turquoise Zone and Meta Junglira Zone, Knuckles appeared before Sonic and Tails and triggered a torrent of flames that blew them away, while in Robotnik Winter Zone, he tried to bury them alive in an avalanche. In Tidal Plant, Knuckles finally decided to face Sonic and Tails head on, here using an underwater vehicle, but was defeated.

Following his defeat, Knuckles was trapped inside a cage in the Atomic Destroyer Zone by Robotnik. Later, after Sonic and Tails had defeated Robotnik, Knuckles was freed from his captivity by the duo, and Knuckles made up on good terms with his friends once more, before taking his leave.

Knuckles' Chaotix
In Knuckles Chaotix, a few months after the events of Sonic & Knuckles, Knuckles noticed one day that a new island had suddenly rose in the southern ocean as a result of tectonic activity simulated by the Master Emerald's presence when Angel Island sank into the sea. What irked Knuckles even more so was that energy from the Master Emerald's pillar was transforming the island from a barren rock into a lush tropical paradise at a unnatural fast rate.

Annoyed with questions about this phenomenon, Knuckles believed that there had to be something on that island that was causing all this, and began to speculated that it held the remains of a legendary civilization that perished long ago. It eventually occurred to Knuckles that something on the island was resonating with the Master Emerald's pillar, amplifying its power. Knuckles, devoted to his duty as guardian, therefore headed out to the island alone to determine if it was threat to the Master Emerald.

When Knuckles arrived on the island, he noticed to his shock that it had been converted into the Newtrogic High Zone by Dr. Robotnik, who had arrived on the island to find the Chaos Rings in order to synthesize Dark Rings that would allow the doctor to summon the Master Emerald and conquer the world. Some time after arriving, Knuckles found Robotnik, who was in the process of trapping Espio the Chameleon in his Combi Catcher. Appearing before the scientist, Knuckles managed to scare Robotnik off, and he freed Espio from his prison. No sooner, Knuckles and Espio saw Robotnik being carried to safety by Metal Sonic, and the two of them decided to team up to free Robotnik's other captives, collect the Chaos Rings, and put a stop to Robotnik's plans.

Together, Knuckles and Espio managed to free Robotnik's other captives, namely Vector the Crocodile, Charmy Bee and Mighty the Armadillo, who joined them in their mission, forming the Chaotix. The group was also joined by Heavy and Bomb, two robots that had deflected from Robotnik's forces. Over the course of their adventure, Knuckles and his group managed to get all six Chaos Rings before Robotnik, and stopped the scientist's usage of the Dark Rings on several occasions.

Eventually, Knuckles and the rest of the Chaotix came under attack by Metal Sonic, who they managed to defeat, though the resulting battle caused them all to fall into a closed battle arena. There, Knuckles and the others were attacked by Metal Sonic Kai, an enhanced form of Metal Sonic and Robotnik's final trump card. Knuckles and the Chaotix still managed to defeat Metal Sonic Kai despite the robot's increased power, thus ending Robotnik's plans and restoring peace to the island.

Sonic the Fighters
In Sonic the Fighters, Dr. Robotnik had gone and built the Death Egg II, from where he prepared to unleash his forces on Earth for conquest. To face this threat, Knuckles entered a fighting tournament where the winner got to collect all the Chaos Emeralds from the other participants, where he himself already had the red Chaos Emerald. Should he win all the Chaos Emeralds, Knuckles would then earn the right to use Tails's Lunar Fox to travel to the Death Egg II and destroy it.

During one of the rounds of the tournament, Knuckles went up against Sonic. Despite his best efforts against his rival, however, Knuckles was defeated by Sonic in a best out of three match. Knuckles then threw a fit as Sonic claimed his Chaos Emerald and advanced in the tournament, with Sonic eventually winning it and managing to destroy the Death Egg II.

Sonic 3D Blast
In Sonic 3D Blast, Knuckles joined Sonic and Tails on their journey to Flicky Island. Having heard legends that the Flicky birds on the island held the key to finding the Chaos Emeralds, Knuckles, Sonic and Tails traveled there in hopes of finding these gems. When the trio finally arrived on the Flicky Island, however, Knuckles and the others found the whole place in disarray. It turned out that Dr. Robotnik had arrived on the island before them and established a base there, from where he trapped the native Flickies in his Badniks and used them to search for the Chaos Emeralds, which happened to be located on the island. Learning of the doctor's nefarious plans and deeds, Knuckles and the others decided to put a stop to Robotnik's plans by freeing the Flickies from their captivity, return them to their home dimension, and collect the Chaos Emeralds first.

While Sonic traveled across the island, freeing the Flickies, Knuckles and Tails helped Sonic find the Chaos Emeralds by taking him to their locations. With Knuckles and Tails's assistance, Sonic was successful in freeing the island from Robotnik's tyranny, and bringing peace back to the island.

Sonic R
In Sonic R, Knuckles heard from some global advertisement that the World Grand Prix, where all the best racers in the world would participate, was about to take place. Once he learned that Sonic was going to participate in this event, Knuckles entered the World Grand Prix himself, not willing to miss the chance to compete against his blue rival once more.

During the World Grand Prix, Knuckles not only went up against Sonic, but also Tails, Amy Rose and Dr. Robotnik and his lackeys, who were using the competition to locate the Chaos Emeralds on the race tracks. At the end of the tournament, Knuckles had been outraced by Sonic, but the heroes managed to keep Robotnik from getting the Chaos Emeralds, ensuring the world's safety once more.

Sonic Adventure
In Sonic Adventure, in the dusk of night, Knuckles was sitting beside the Master Emerald at its altar, drifting to sleep while lamenting the story of his life. Suddenly, he was awakened by a noise, and found Chaos next to the shattered Master Emerald. Shocked and enraged at the damage done to the relic, Knuckles assumed that Chaos was behind it and attacked it, but it blindsided Knuckles and send him flying off the altar, before escaping. Because of the Master Emerald's absence, Angel Island fell into the sea.

Knowing that the Master Emerald could be restored if he found all its fragments, Knuckles left Angel Island to search for its wide-scattered Emerald Shards. After finding the Emerald Shards in Speed Highway and Casinopolis in Station Square, Knuckles was pulled into the past of the Mystic Ruins when the Knuckles Clan was still thriving, by Tikal's spirit. While there, Knuckles witnessed Tikal's futile attempts to convince Pachacamac of abandoning his warmongering ways, before he was sent back to the present.

Confused about what had happened, Knuckles spotted Dr. Eggman and a shine in doctor's hand, which Knuckles believed to be an Emerald Shard. After cornered Eggman, however, Knuckles saw that the doctor possession was a Chaos Emerald, before giving it to Chaos 1, transforming it into Chaos 2. Recognizing the creature, Knuckles attacked and defeated Chaos 2. After the battle, Knuckles was told by the departing Eggman that Sonic was after the Emerald Shards too. Wondering why Sonic wanted the shards, Knuckles decided to find Sonic to get some answers.

After finding more Emerald Shards in Red Mountain, Knuckles found Sonic and Tails. Seeing a shine in Sonic's hands, Knuckles believed it was Emerald Shards, and attacked them, demanding the Emeralds back. Knuckles then fought Sonic for a while until Sonic lost his two emeralds, for then to have Eggman nab them. Knuckles saw that they were actually Chaos Emeralds and was surprised when Eggman revealed that he had tricked him so he could steal the Chaos Emeralds. Eggman then gave the Chaos Emeralds to Chaos 2, causing it to transform into Chaos 4, but Knuckles, Sonic and Tails defeated Chaos 4. As Eggman left in the Egg Carrier, with Sonic and Tails going after him, Knuckles went to find the rest of the Emerald Shards.

After finding more Emerald Shards in Lost World, Knuckles was sent back to the past again, where he saw Tikal attempt to make Chaos leave the Altar of the Emeralds with the Chao. Knuckles was then sent back to the present again, in front of the present-day alter. There, Knuckles tried to restore the Master Emerald, but saw it was still missing a few pieces. Knuckles then saw the Egg Carrier's image in the Master Emerald and deduced that it was the location of the last Emerald Shards.

As he left the altar, Knuckles spotted E-102 Gamma and decided to trail the robot to the Egg Carrier. On the Egg Carrier, Knuckles found the last of the Emerald Shards and prepared to return home, but was then sent to the past again, where he found the alter ablaze. He walked over to Tikal and attempted to find out what was going on, but was send back to his time. Back on the Egg Carrier, Knuckles tried to leave, but then spotted Eggman and Sonic. Meeting with Sonic, who went after Eggman shortly after, Knuckles fought and defeated Chaos 6, making it relinquish the six Chaos Emeralds it had absorbed. When the Egg Carrier then began to self-destruct, Knuckles glided back to Angel Island with the six Chaos Emeralds. Back at the Island, Knuckles fully restored the Master Emerald, allowing the giant gem to hoist Angel Island back to the heavens.

Not long after, however, the Angel Island soon fell back down from the sky again. Knuckles, baffled as to why this had happen, decided to find Sonic for advice, believing the Chaos Emeralds he had brought back with him had something to do with it. Soon after, however, he found Eggman beaten up, before being ambushed by Chaos, who took his Chaos Emeralds. Knuckles was later found by Sonic and Tails and he informed them of Chaos's return and warned them that Chaos would destroy the world with the Chaos Emeralds, before telling them to keep the last Emerald safe.

Knuckles later traveled to Station Square where Perfect Chaos was on a rampage. There, he found four of the now-drained Chaos Emeralds, and brought them to Sonic, somewhat reluctantly agreeing with Tails that Sonic could still harness the Chaos Emeralds' positive Chaos Energy to stop Chaos. Knuckles then saw Sonic transform into Super Sonic and defeat Perfect Chaos. After the battle, Knuckles looked on with content as Chaos was returned to a peaceful creature once more and departed with Tikal.

Sonic Shuffle
In Sonic Shuffle, Knuckles was hanging out with Sonic, Tails and Amy, when they were suddenly transported into Maginaryworld. After landing in the Temple of Light, Knuckles took a look around their new location and wondered if they were all dreaming. Here, the group met a fairy-like being named Lumina Flowlight, the person responsible for transporting them to Maginaryworld.

Knuckles asked Lumina where they were, and she introduced Maginaryworld to him and the others. Lumina then explained that they were brought here to help save the Precioustone, the object that sustained Maginaryworld, which had been shattered by Void when he tried to steal it. Its pieces were then scattered to different part of this world and had made their ruler and protector of the Precioustone, Illumina, vanish as well. As Lumina explained that she needed Knuckles and the others' help to recover the pieces of the Precioustone, or Void’s darkness would bring Marginary World's end, Knuckles agreed to help, remarking that he got nothing better to do.

The party began their adventure by recovering the Precioustone pieces from the different worlds within Maginaryworld, and restore the places affected by Void. Each time after finding a Precioustone piece, Knuckles and the others had a vision where they saw and interacted with Void. While Knuckles and the gang initially stood against Void, with Knuckles insisting on protecting this world, they began to see that Void showed signs of depression and loneliness which touched their hearts, and they began to see that there were more to Void than they believed.

After Knuckles and the others had collected the missing Precioustone pieces and returned them to the Temple of Light, they went back to the temple as Void was going there to seek out the gem again. When Knuckles and the others got to the temple to stop Void, Void claimed he just want to become whole, but never could. With Knuckles and the others rejecting him, Void’s loneliness and despair reached its peak and he transformed into a monster.

Knuckles, Sonic and Tails and Amy fought and defeated Void, but Lumina gave into despair as the Precioustone was not recovering and feared it was the end of her world, despite Knuckles telling her it could not end like this. When Sonic found Void in the form of a dark gem, Knuckles and the others understood that Void and Lumina embodied the positive and negative aspects of dreams and were two halves of the same being. As the group tried to make Lumina accept Void, Knuckles told her that people only lose their dreams when they give up on themselves, a fact that he remarked Lumina should know all about.

With everyone’s help, Lumina understood that both positive and negative feelings were necessary for dreams to exist. Knuckles and the group then witnessed Lumina restoring the Precioustone, and Lumina and Void returning to their original form, Illumina. As Marginaryworld was restored to an even better place, Knuckles and the gang heard Illumina explaining that it was her own despair that split her into Lumina and Void. With Illumina's gratitude, Knuckles and the others returned to their own world.

Sonic Adventure 2
In Sonic Adventure 2, Knuckles discovered that the Master Emerald had been stolen by Rouge the Bat. Tracking her to a desert area, Knuckles confronted Rouge and got into an argument with her about the ownership of the Master Emerald, when the gem was suddenly stolen by Dr. Eggman, who arrived hoping to find the Chaos Emeralds. When Eggman tried to escape, Knuckles purposely shattered the Master Emerald, scattering its Emerald Shards everywhere, to prevent the theft. Knuckles was berated by Rouge for smashing the Master Emerald, but Knuckles told her why he did that and that he could reform it later, before Rouge left to find the shards herself.

Beginning his search for the Emerald Shards, Knuckles managed to find some in Wild Canyon, Pumpkin Hill and Aquatic Mine. After finding the Emerald Shards in Aquatic Mine, Knuckles got lost in the tunnels inside the mines and ended up at Central City. Knuckles came across Tails and Amy as he found himself dragged into Sonic's latest adventure by Amy, where she, Sonic and Tails are trying to stop Dr. Eggman from using the Eclipse Cannon to hold the Earth hostage and take over the world.

Having located Eggman on Space Colony ARK, Knuckles led the group to Eggman's pyramid base, having witnessed both Eggman and Rouge enter it. Believing there was a space shuttle in there that they could use to get to Space Colony ARK and destroy the Eclipse Cannon, Knuckles and the others infiltrated the base, where Sonic had Knuckles volunteer to find the keys to the base's center. After finding the keys, Knuckles was attacked by King Boom Boo, but defeated him. After having gaining access to the launch pad of the shuttle, Knuckles and the others were ambushed by Eggman with the Egg Golem. While Sonic dealt with and defeated the Egg Golem, Knuckles and the others got onboard a space shuttle, with Sonic joining them just in the nick of time.

While en route to Space Colony ARK, the group's space shuttle hit a stray asteroid, causing the cargo bay to open and releasing the Emerald Shards that were stored there. Panicking, Knuckles tried to get back to get them by taking control of the shuttle, only to cause it to crash land on Space Colony ARK. After the landing, Knuckles left the group to find the lost Emerald Shards.

Arriving in Meteor Herd, Knuckles managed to find some Emerald Shards, before meeting Rouge again where he was through talking with her and engaged a fight with her. As they battled to a stalemate, Knuckles saved Rouge's life when she tripped and nearly fell into a magma pit. Despite this, Knuckles was berated Rouge, who believed he did it just to hold her hand. Angry at her treatment, Knuckles told Rouge that he did it to save her Emerald Shards. Regardless, Rouge returned her Emerald Shards to Knuckles as thanks, and Knuckles finally restored the Master Emerald. As he left, Knuckles swallowed his pride and apologized to Rouge in the case that he hurt her.

After having made it back inside, Knuckles sensed Chaos Energy and witnessed Sonic appearing in front of him with Chaos Control when he esacped from an exploding capsule with a fake Chaos Emerald. Knuckles was then told by Sonic to go help Tails and Amy, before Sonic left to destroy the Eclipse Cannon.

When Knuckles and Sonic arrived in the Space Colony ARK's main control room after the Eclipse Cannon was stopped, they met Rouge, who told them that the ARK was on a collision course with Earth. Knuckles and the others then saw a recording of Gerald Robotnik announcing to the world that the ARK's impact would destroy the planet, wiping out the human race as his revenge at the world for the death of his granddaughter, Maria. Banding together with Eggman, Knuckles agreed with Rouge's plan to use the Master Emerald to deactivate the seven Chaos Emeralds, which was powering the cannon's core, to stop the Space Colony's crash course.

When Knuckles and Sonic made it to the core, they were attacked by the Biolizard, but Shadow arrived and held it off. Getting to the shrine, Knuckles used the Master Emerald and neutralized the Chaos Emeralds. In response, however, the Biolizard warped outside the ARK and merged with it, becoming the Finalhazard and kept the ARK on its collision course. Knuckles then saw Sonic and Shadow using the Chaos Emeralds to become Super Sonic and Super Shadow, and gave them advice against the Finalhazard through transmission lines.

After Super Sonic and Super Shadow had defeated the Finalhazard and brought the Space Colony ARK back into orbit, Knuckles and the others found Sonic returning alone, informing them that Shadow had seemingly died. Knuckles then asked Rouge what she planned to do next, expecting her to continue her hunt for jewels. Rouge, however, told Knuckles that she considered giving up that profession, something Knuckles was content with. Soon after, Knuckles and the others returned to Earth.

Sonic Advance
In Sonic Advance, Knuckles joined forces with Sonic, Tails and Amy to stop Dr. Eggman from obtaining the seven Chaos Emeralds. Over the course of their adventure, Knuckles and the others chased after Eggman to stop his scheme while defeating the doctor on a number of occasions and got the Chaos Emeralds first. The group eventually followed Eggman into space, where they confronted him in the X-Zone. After they defeated the Egg X, Knuckles, Tails and Amy returned to Earth, while Super Sonic faced Dr. Eggman in a final confrontation on the Moon. As Sonic seemingly disappeared following his victory over Eggman, Knuckles and the others wondered what had happen to Sonic as they awaited his return. A few days later though, Sonic finally returned to Earth.

Sonic Advance 2
In Sonic Advance 2, Knuckles was kidnapped alongside Tails by Dr. Eggman when the evil scientist attempted once more to create the Eggman Empire. After being captured, Knuckles was somehow tricked by Eggman into fighting Sonic for him.

In Sky Canyon, Knuckles intercepted Sonic and his allies in the Egg Saucer, but was defeated. As the Egg Saucer was destroyed, Knuckles was badly burned in the process, causing him to furiously chase after Sonic and the others. Realizing that he had been tricked, Knuckles tried to defend himself by telling Sonic how circumtances had made him fight him. Sonic however, chided Knuckles for being duped by Eggman again, causing Knuckles to become very emotional. When Sonic then tried to leave, Knuckles joined Sonic in his mission to beat Eggman, wanting payback at Eggman.

After seemingly beating Eggman, Knuckles, Sonic, Tails, Cream and Cheese found Vanilla the Rabbit who had gone missing, only to see her being kidnapped by Eggman in his new mech, making Knuckles quietly disappointed at the turn of events. Knuckles then witnessed Sonic using the Chaos Emeralds to become Super Sonic and taking off to rescue Vanilla and stop Eggman. When Sonic shortly after returned with Vanilla, now having beaten Eggman, Knuckles managed to congratulate Sonic for a job well done before the hedgehog took off on his own.

Sonic Advance 3
In Sonic Advance 3, the Earth was split into seven regions by a massive Chaos Control induced by Dr. Eggman, who planned to turn each region into a part of the Eggman Empire. In this distorted world, Knuckles came across Sonic and Tails, who were trying to put the world back to normal, in Sunset Hill. Upon meeting them, Knuckles asked Sonic what was happening this time, before smugly offering them his help. Sonic, however, declined Knuckles's offer, something Knuckles was slow to get. When Knuckles finally realized what Sonic said, he saw that they were leaving and he tried follow them.

Despite his rejection, Knuckles joined Sonic and Tails in their mission. After traveling across the different regions, collecting the seven Chaos Emeralds, and having Amy and Cream join them along the way, Knuckles and the others made it to the Altar Emerald. After defeating the Hyper EggRobo, Knuckles and the others used the Master Emerald to return the world to normal. Later, following Sonic's return from his and Eggman's battle with Ultimate Gemerl, Knuckles remained behind at the Master Emerald's shrine and watched on satisfied when his friends took their leave as their adventure came to a close.

Sonic Heroes
In Sonic Heroes, Knuckles and Tails received a letter from Dr. Eggman, who claimed to have created "the ultimate weapon" to conquer the world and challenged them to stop him within three days. Using the Tornado 2, Knuckles and Tails began looking for Sonic, and eventually caught up to him where they brough him the news. As Knuckles was confident they could handle it, he and Tails joined Sonic as he took off to stop Eggman's scheme, officially forming Team Sonic.

Knuckles and the team began their mission by tracking down Dr. Eggman, and eventually him where they were attacked by the Egg Hawk. Though they defeated the Egg Hawk, Eggman managed to escape. After this, Team Sonic tracked Eggman to Grand Metropolis, which Knuckles noted Eggman had escaped into. After the team managed to free the city from Eggman's control and escape from the Power Plant, Knuckles and the others came across Team Rose.

After a brief forced fight, Team Sonic managed give Team Rose the slip. Arriving in Casino Park, Knuckles was taken back by the place and its bright lights, but was pushed on as they only had 24 hours left to stop Eggman. As they got through the city, Eggman attacked them with his Robot Carnival, but Team Sonic defeated the robots. After tracking Eggman to Rail Canyon and only having until sunset, Knuckles went full speed for the terminal station on Sonic's command. When they reached Bullet Station and destroyed Eggman's base there, Team Sonic found Eggman in the Egg Albatross, which Knuckles noted was loaded with weapons, just before they ran out of time. After destroying the Egg Albatross, Knuckles and the team discovered that the Eggman they had been chasing was a copy, and that their challenge was to distract them while Eggman launched his Egg Fleet. As Sonic took off in pursuit of Eggman, Knuckles quickly followed him.

Followed Eggman through the jungle, Team Sonic came across Team Dark, where Knuckles was surprised to see that Shadow was still alive. No sooner, Knuckles got angry at Rouge when she told them to let Team Dark take over their chase for Eggman, and things escalated to a fight between the two teams. After the battle, Team Sonic followed Eggman and Shadow to Hang Castle. When Tails freaked out by the place, Knuckles teased him by saying that it could have been Shadow's ghost they had seen. After infiltrating the castle, Team Sonic escape Mystic Mansion, where they were attacked by Eggman's Robot Storm, but defeated it.

Afte that, Team Sonic traveled to the Egg Fleet, heading straight for Eggman's headquarters. Eventually, Knuckles, Sonic and Tails arrived at the Final Fortress and destroyed the colossal flagship's core. Team Sonic then found Eggman, with Knuckles telling the doctor to give up, before fighting Eggman in his Egg Emperor and defeating him. After destroying much of the Egg Fleet, Knuckles teased Sonic with the fact that he had stood no chance without their help when Sonic with Knuckles disagreed on how close it was this time, but was surprised to hear Sonic agree. Knuckles and Tails stood by and watched Sonic making his escape as Amy arrived.

Later, Team Sonic and the other teams witnessed the return of Metal Sonic, who had been staging the team's adventures and impersonating Eggman so he could follow them and copy their data in a plan to conquer the world himself, as he transformated into Metal Madness. Seeing that the teams had collected all the Chaos Emeralds, the real Dr. Eggman came up with the plan of using them against Metal Sonic. When Sonic decided to face Metal Sonic alone, Knuckles and Tails decided to go with him. While Team Sonic charged the Chaos Emeralds, Team Rose, Team Dark and Team Chaotix fought Metal Madness to buy them some time.

When Metal Madness transformed into Metal Overlord, Team Sonic used the Chaos Emeralds to transform Sonic into Super Sonic and make him grant Knuckles and Tails a Super Shield each. The team then took off and defeated Metal Overlord. Back on the flagship, Sonic took his leave after seeing Amy, Knuckles remarked that Sonic had his hands full, before Rouge told him that she would steal "someone else's treasure." Initially amazed by Rouge's persistence, Knuckles realized that she referred to the Master Emerald and ran after her. Sometime after, Knuckles joined Sonic and Tails as they headed off to find their next adventure.

Shadow the Hedgehog
In Shadow the Hedgehog, Knuckles left his post on Angel Island and joined forced with most of his friends and G.U.N.'s forces to repel the Black Arms invasion of Earth. He appears during Shadow's Hero Missions where he asks Shadow for assistance against the Black Arms.

Glyphic Canyon
Arriving in Glyphic Canyon, Knuckles attempted to assist G.U.N. by driving off the Black Arms infesting the area. There, he met Shadow, who had just been teleported to the ruins. Upon meeting him, Knuckles filled Shadow in on the Black Arms around them, and requested his assistance in clearing the area of the Black Arms.

In the Hero scenario, where Shadow accepted Knuckles's request, Knuckles and Shadow managed to drive the Black Arms out of the area, and as well finding one of the Chaos Emeralds amongst the ruins.

Central City
In Central City, Knuckles discovered that the Black Arms had set up bombs across the city that would destroy the entire city should they detonated, a tragedy that Knuckles did not intend to come true. When there was only a few minutes left until the bombs would explode, Knuckles noticed Shadow had arrived in Central City, and told him that he had timed it well, before asking for his help in defusing the bombs.

In the Hero scenario, where Shadow accepted Knuckles's request, Knuckles and Shadow succeeded in defusing enough bombs and managed to save the city.

Black Comet
Under unspecified circumstances, Knuckles managed to get onboard the Black Comet. There, Knuckles assisted G.U.N. in attacking and bringing down the Black Arms' base, with Knuckles planning to get to the center of the Black Comet and destroy it. As he worked his way through the alien grounds, Knuckles came across Shadow. Upon meeting him, Knuckles told Shadow that this was the final showdown and that he would personally destroy the Black Comet himself, before asking Shadow for his help to get to the center.

In the Hero scenario, where Shadow accepted Knuckles's request, Knuckles and Shadow made it to the center of the Black Comet, where they found the Chaos Emerald that the Black Arms had stolen. Though Shadow refused to follow Knuckles any further after getting the Emerald, Knuckles still came to Shadow's aid when the hedgehog was attacked by Dr. Eggman and his Egg Dealer. Eventually, the two of them managed to destroy Eggman's contraption and as well claim the final Chaos Emerald.

Last Story
In the last story, Knuckles arrived with Sonic, Tails, Amy, Rouge and Dr. Eggman to stop Shadow from giving the Chaos Emerald to Black Doom. Black Doom however, took the emeralds himself and used an enhanced Chaos Control to transport the Black Comet to the surface, planning to use humans as energy sources for his kind. Intending to stop Black Doom's scheme, Knuckles voiced his intention to crush the Black Comet for good, only to be paralyzed by a special nerve gas along with the others, and Black Doom unleashed the Death leeches to prey on them. Shadow however, proved to be immune to the gas, and he left Knuckles and the others behind as he pursued Black Doom.

Knuckles and the others eventually managed to escape the Black Comet and find some shelter from where they cheered Super Shadow on as he fought and defeated Devil Doom. Knuckles then witnessed Super Shadow sending the Black Comet back into space and blowing it to pieces with the fully charged Eclipse Cannon, saving the planet. As Eggman then tried to sneak away to claim the Chaos Emeralds, Knuckles began to furiously after Dr. Eggman to keep him from escaping.

Sonic Battle
In Sonic Battle, while attending his own business, Knuckles heard from the news that an E-121 Phi had been robbing jewelry stores. Later, at his house in Holy Summit, Knuckles met Sonic and Tails and Emerl, a Gizoid Sonic had found, who had come to ask for the Chaos Emerald in Knuckles's possession to develop Emerl. Knuckles, however, mistook Emerl for an E-121 Phi and attack him, but was defeated. Admitting defeat, Knuckles relinquished his Chaos Emerald, before hearing about Emerl's abilities and that Eggman and Rouge were after Emerl, which made Knuckles suspect that something was up.

After Tails had been to Central City, Knuckles met Tails and Emerl. As Knuckles tried to converse with Emerl, he was infuriated when Emerl first ignored him and then began repeating Knuckles and Tails' words, which provoked Knuckles to fight Emerl, but defeated. Knuckles was then told by Tails to meet them on Emerald Beach, intending to tell them that Emerl was an ancient weapon of mass destruction, when he noticed that their path was blocked by Chaos Gamma. After fighting Chaos Gamma, Knuckles got Tails and Emerl to leave while he finished the robot. When Chaos Gamma escaped, Knuckles got to Emerald Beach, where he saw Rouge leaving the scene and heard what had happen from Sonic. When Knuckles tried to ask Emerl if Rouge pulled any tricks on him, he became infuriated as Emerl continued to ignore him, especially upon Sonic's orders, which made Knuckles fight both of them.

Later, after Emerl had been stolen by Rouge, Knuckles and Tails came to Sonic's aid when Sonic fought Rouge to get Emerl back, which eventually ended with Rouge surrendering Emerl. Later on, when Knuckles caught the news about how Emerl needed Chaos Emeralds and that he grew stronger the more he fought. Gaining an interest in Emerl, Knuckles vowed to help him realize his full potential and left to find him. Finding Emerl with Tails in Emerald Town, Knuckles offered Emerl to train him. After sparring with Emerl, Knuckles heard the news say that an E-121 Phi had appeared in Night Babylon, and Knuckles took Emerl with him to deal with it.

As they got to Central City, Knuckles came across Amy, who asked him where Sonic was, but excused himself as they left, only to be attacked by Chaos Gamma. After forcing Chaos Gamma to leave and wondering about how it seemed to be after Emerl, Knuckles encountered Rouge, who filled him in on Chaos Gamma and learned that he robot wanted revenge at Emerl. As Knuckles processed this, he noticed Rouge had left, and he and Emerl continued to Night Babylon.

At Night Babylon, Knuckles questioned a store clerk about the E-121 Phis. However, the clerk mistook Emerl as the E-121 Phi and called a Guard Robo to capture them. After destroying the Guard Robo and accidently wrecking the Night Club, Knuckles and Emerl made their escape. While escaping, Knuckles lost his temper and yelled at Emerl, upsetting him. Apologizing for his outburst, Knuckles asked Emerl to wait while he went ahead. When Knuckles returned later, he noticed Emerl was gone and began to look for him. After several kermises with store clerks due, Knuckles arrived at Club "Rouge", where he found Emerl with Rouge. Knuckles asked Rouge what she wanted with Emerl, but found her innocent. Just then, Knuckles found the E-121 Phis, and he and Emerl fought them. After destroying the E-121 Phis, Knuckles and Emerl got their Emerald Shards, and were then given a Emerald Shard from Rouge as well (though she asked for the Master Emerald in payment). Rouge then suggested that they asked Tails about the Emerald Shards.

Returning to Emerald Town, Knuckles asked Tails about the Emerald Shards. After hearing that they could form a whole Chaos Emerald if the collected two more shards of the same color from the E-121 Phis, Knuckles left with Emerl to make him strong enough to face them and faced him in a battle to settle his score with. Though he was defeated, Knuckles was happy about his loss. Just then, Dr. Eggman appeared and attacked them with a E-121 Phi, but Knuckles and Emerl defeated it, claimed its Emerald Shard, before chasing Dr. Eggman. After finding Eggman in Central City, Knuckles and Emerl destroyed another of the doctor's E-121 Phis and took its Emerald Shard. There, Knuckles proclaimed Emerl as his battle partner, before hearing Eggman say that he was heading to Gimme Shelter, leading to Knuckles heading to there to catch Eggman.

At Gimme Shelter, Knuckles was caught in Eggman's "spiky rodent trap" where he realized that he had been tricked into following Eggman. After hearing Eggman's plan to have Emerl absorb his Final Egg Blaster, he was left at the mercy of Chaos Gamma, but Emerl defeated the robot. Afterward, Knuckles asked Emerl to free him. Emerl, however, scoffed Knuckles for his lack of strength, infuriating him enough to try and break through the trap with brute force, until Emerl finally freed him. Heading back to Emerald Town, Knuckles had Tails assemble their Emerald Shards to a whole Chaos Emerald, which they inserted into Emerl. As Tails asked them of what had happened, Knuckles asked Emerl to keep it a secret that he got tricked by Eggman. Regardless, Emerl still told it to Sonic and Tails, causing Knuckles to explode with anger.

Later on, after Emerl had been reset of his destructive programing by Shadow, Knuckles met Emerl again, who had come to fight him, where he was still defeated. Later, awhen Eggman revealed his newest Death Egg and its Final Egg Blaster, Knuckles met up with Sonic, Tails and Emerl at Holy Summit, where he revealed that Chaos had returned, which was a sign of grave danger. As Emerl vent to the Death Egg to stop Eggman  Knuckles and the others watched Emerl through a monitor and cheered him on.

When Eggman was defeated, however, Eggman fired the Final Egg Blaster, destroying some stars. This display of power caused Emerl to revert to his original programming and Eggman tried to take control over Emerl, but he knocked Eggman away and prepared to fire the Final Egg Blaster on Earth. Knuckles then urged Sonic on as he went to the Death Egg with the Master Emerald to stop Emerl, but Emerl smashed the Master Emerald. As a last resort, Sonic had no choice but to destroy Emerl. Once the deed was done, the world was saved, but everyone lamented over Emerl's death.

Sonic Rush
In Sonic Rush, Knuckles was walking around on his own, when he suddenly met Cream. Upon greeting her, Knuckles was brought over to meet Cream's new friend Blaze the Cat, but took some offense to Cream when she introduced him to Blaze as being not very bright. Knuckles then asked Cream impatiently to introduce him to Blaze, and Cream complied. Knuckles, however, thought Blaze looked suspicious, and noticed that Blaze was holding a Sol Emerald. Sensing that its power was similar to Chaos Energy, Knuckles believed it to be a Chaos Emerald and asked Blaze if it really was one, before advising her to give it to Sonic for safekeeping. Blaze, however, rudely denied to have any Chaos Emeralds and tried to leave. Knuckles, however, thought that Blaze was lying and tried to chase after her, but ended up getting buried in a pile of rocks by her.

After some time, Knuckles managed to pull himself out of the rocks and found himself facing Sonic and Tails, who were looking for Blaze. When Tails asked Knuckles how he got stuck there, Knuckles had only just recovered before telling Sonic and Tails infuriated that it was because of Blaze that he got stuck there. Now extremely angry at having been stuck, Knuckles ignoring Tails's questions and took off to punch some things to went his anger, inadvertently opening a path blocked by rocks in the process.

Following that, Knuckles went searching for Blaze to get some payback at her, and eventually found her with Cream and Amy. Before he could get to Blaze though, Knuckles was stopped by Amy. As Knuckles told Amy that his business was only with Blaze, he saw to his discontent that Cream was flying away with Blaze and had no means of pursuing them.

In the aftermath of Sonic and Blaze's battles with Dr. Eggman and Dr. Eggman Nega respective Egg Kings, Knuckles joined up with the others in celebration. No sooner, Knuckles warned Sonic that Amy was coming, and watched as Sonic tried to escape from Amy.

A while afterwards, Knuckles, along with Sonic, Tails, Amy and Cream, came to Blaze's aid after Eggman and Eggman Nega had drained all her seven Sol Emeralds of their power in order to conquer both Sonic's dimension and the Sol Dimension. After everyone had cheered Blaze on, Knuckles, now holding no hostile intentions towards Blaze, urged her and Sonic to defeated Eggman and Eggman Nega. With Knuckles and the others' support, Blaze recharged the Sol Emeralds and became Burning Blaze and joined up with Super Sonic, and together, they defeated the doctors and saved both worlds.

Sonic Riders
In Sonic Riders, Team Sonic arrived in Future City as they searched for a Chaos Emerald, until suddenly a group of thieves on Extreme Gear, called the Babylon Rogues, revealed themselves. When Tails read on his radar that the Emerald was in their possession and Sonic ran off to intercept them, Knuckles came to Sonic's aid and managed to knock Storm the Albatross off his Type-S, though Storm still managed to escape, much to Knuckles's frustration. After Sonic took off on the Type-S to catch Jet the Hawk, Knuckles and Tails followed him and eventually found Sonic, who had been knocked down while the Babylon Rogues escaped.

The next day, Knuckles, Sonic and Tails saw Dr. Eggman on the local monitors, announcing the EX World Grand Prix and that the entry fee for the contestants was a Chaos Emerald, with the winner getting the right to claim all seven. Seeing that the participants Dr. Eggman had rounded up were the Babylon Rogues, Knuckles and the others decided to enter the competition and uncover Eggman's plot.

After the qualifications rounds, Knuckles was wondering about what Eggman was up to, when he and his team met Amy, who had also signed up for the tournament. Knuckles then heard Tails tell the legends of the Babylon Rogues after having seen the mark on Storm's Extreme Gear and how the Babylonians lost their home island, Babylon Garden, and its treasure. After hearing the legend, Knuckles asked Tails how Extreme Gears could float, but found his explanation too confusing, and told him to stop. Just then, Wave the Swallow came by and mocked Tails's Blue Star (and places a bomb on it), with Knuckles finding her behavior especially misfitting. Shortly after, Knuckles and the others hurried out to next race after hearing the call.

After the race, Knuckles was walking through the Egg Factory when he suddenly bumped into Storm. Recognizing him from Future City, Knuckles wanted to settle things between them, and was ready to fight Storm when he accidently hit a E-10000R. When Storm then tried to punch Knuckles while he was distracted, Knuckles got him to hit the E-10000R, though he got angry when Storm blamed him for it. They then heard that the next race was about to start, and Knuckles and Storm decided to settle their dispute with a race, which Knuckles managed to win.

Before the semifinals, Knuckles and Tails watched Sonic practice his Extreme Gear techniques, with Knuckles being amazed by Sonic's performance, until Jet appeared and mocked Sonic's skills at Extreme Gear before taking his leave, making Knuckles think Jet thought too highly of himself.

Eventually, Knuckles and his team made it to the finals, which Jet managed to win after Wave sabotaged Sonic's Blue Star. Knuckles and the others then witnessed Jet claim and use the seven Chaos Emeralds in tandem with the Key to Babylon Garden to reveal Babylon Garden itself, with the intention of claiming its treasure. Eggman, however, stole the key so that he could take the treasure for himself, believing it to be technology that he could use to conquer the world, and Knuckles and Tails followed Sonic as they headed out to stop Eggman. Using the Tornado 2, Knuckles and Tails made it to Babylon Garden, while Sonic took off on the midway to chase Eggman. There, Knuckles and Tails met Wave and Storm, and Knuckles and Storm got ready to fight each other, but had to stop when a flock of E-10000 robots attacked. Hearing Wave call him a "red mutt", Knuckles chased after Wave in his rage, and eventually arrived at Sonic's location with Tails as Sonic stopped Eggman and returned the Key to Babylon Garden to Jet. As the Rogues headed in to claim the treasure, Knuckles and the others were about to leave when Amy arrived, furious at Sonic for attack Eggman while he held her hostage. Knuckles and Tails when watched as Amy chased Sonic around, until they heard a heard a roar and decided to check it out. Arriving inside Babylon Garden, Knuckles and the others saw that the Babylon Rogues had awoken the Babylon Guardian and were forced to fight it.

After beating the Babylon Guardian, the group found the Treasure of Babylon, which was revealed to be a Magic Carpet, much to the disappointment of Eggman, who had just arrived to steal it. With the whole ordeal over, Team Sonic and the Babylon Rogues went their separate ways, until they would meet again.

Sonic Riders: Zero Gravity
In Sonic Riders: Zero Gravity, a few months after the EX World Grand Prix, Knuckles was driving with Sonic and Tails through Monopole with a mysterious meteorite Tails had found the other night. On their way to Megalo Station, however, Knuckles and the others were attacked by SCR-HD and a group of SCR-GP, a part of a currently global robot rampage who were after the meteorite. In the insuring chase, the group crashed and fell out from the 300th floor. Using his gliding skills, Knuckles broke his fall alongside Tails, and saw Sonic use the meteorite to manipulate gravity and save himself.

Joining up with Sonic, Knuckles the others tried to hide from the robots. There, they met Amy, who was being chased by the robots because she had a meteorite similar to Sonic's. The group then planned to go to MeteorTech, who created the robots, for some answers. After arriving at MeteorTech, Knuckles and the gang were discovered by security, but then the Babylon Rogues arrived, and Jet repelled the security robots with another meteorite. As the Babylon Rogues revealed that they were after the meteorites, called the Arks of the Cosmos, Knuckles was ready to fight Storm when he challenged him, but had to wait when the alarm sounded and more robots showed up.

Arriving in the control room, Knuckles and the others were surprised to find Dr. Eggman, who owned of MeteoTech, though Eggman claimed to have no part in the global robot rampage. However, when Eggman recognized the Ark of the Cosmos on Sonic's wrist, the group realized Eggman knew something, and Knuckles threatened the doctor to tell them. Eggman revealed that MeteoTech’s computer was powered by one of the Arks of the Cosmos and that the robot leader, SCR-HD, which also had an Ark of the Cosmos, sought them out for reasons unknown. The group then noticed that Amy was being chased by SCR-HD, and Knuckles, Sonic and Tails left to save her.

When they found Amy, Knuckles and the others learned that SCR-HD had suddenly blown up and that Storm had taken its Ark of the Cosmos. Knuckles thought it meant the robot rampage would now end, but Tails deduced that they had to remove the Ark of the Cosmos in MeteoTech’s mother computer to stop the robots. As Amy remembered a place that Storm mentioned with info on the Arks of the Cosmos, Knuckles recognized it as Gigan Rocks. Telling the others of the legends surrounding the place, though he warned them that no one had returned from there alive, Knuckles personally lead the group there.

Arriving at Gigan Rocks, Knuckles noticed that the Ark of the Cosmos resting there was gone. As Knuckles translated some ancient inscriptions, the group learned that the Arks of the Cosmos were ancient power units for Babylon Garden. After then seeing the Babylon Rogues chase after Eggman above them, Knuckles translated some more inscriptions, which made the group figure out the location of Eggman’s Ark of the Cosmos and MeteoTech’s computer mother. When they arrived there, Knuckles and the others found the Crimson Tower and the Babylon Rogues, who revealed that Eggman had stolen their Arks of the Cosmos. Understanding that Eggman planned to use the Arks of the Cosmos to control all the world's robots and conquer the world, Knuckles and the others raced against the Babylon Rogues to Eggman, with the winner getting all the Arks of the Cosmos.

At the end of race, Eggman was stopped and the robot rampage came to an end. After Babylon Garden had revealed itself due to all Arks of the Cosmos being present and handing over their Arks of the Cosmos, Knuckles, Sonic and Tails were about to leave when SCR-HD suddenly appeared and took all five Arks of the Cosmos to Babylon Garden. This resulted in Babylon Garden transforming into Astral Babylon and to form a black hole that threatened to consume the planet. Knuckles and Tails then followed Sonic to Astral Babylon to disconnect the engine, with the Babylon Rogues just behind them. There, they faced Master Core: ABIS, who had merged with the black hole. However, by using its own power against it, Knuckles and the others stopped Master Core: ABIS and saved the world.

With the world safe once more, Knuckles, Sonic, Amy and Tails returned to Monopole, where Tails told Knuckles and the rest that the Arks of the Cosmos had a program which caused the robots to go amok and to collect them when they were hit by their influence. Knuckles and then others then found Jet flying by, who challenged Sonic to a new race, which Sonic accepted.

Sonic Free Riders
In Sonic Free Riders, Knuckles and the rest of Team Sonic entered the newest World Grand Prix, which was once again hosted by Dr. Eggman (under the alias as King Doc) as Team Heroes. Knuckles and the team however, simply participated for the sake of the competition and the chance to get the title of world's fastest team, rather than the large cash price. When introduced to the viewers of the races, Knuckles was pumped up and impatiently waiting for the competition to begin.

For their first race, Team Sonic went up against Team Rose. Knuckles, however, hardly felt threatened by Team Rose, not even consider them worth a warm-up. Additionally, Knuckles found Amy dense as she berated Sonic for not going easy on them. After besting Team Rose, Omochao asked Knuckles for comments, and Knuckles remarked that they would not last long if they let this victory go to their heads.

In their next race, Team Heroes went up against Team Dark. When Knuckles went up against E-10000B, however, he heard the robot making clicking sounds and moving around funny. After the race, Knuckles confronted E-10000B, suspecting foul play. However, as no proofs of Knuckles's claims could be found, he was forced to abandon his accusations, though Knuckles warned that he would keep an eye on E-10000B. Regardless, Team Heroes still beat Team Dark, and advanced to the finals.

In their final race, Team Heroes went up against Team Babylon. With Team Babylon confident of their victory, Knuckles aggressively expressed his readiness to fight them for the championship. Over the course of the team face-off, Knuckles supposed both his team and mocked Team Babylon as their victory slipped away. After defeating Team Babylon, even when the opposing team was given a second chance due to mechanical trouble, Knuckles was asked for comments, and he said that that he had a good time, since he managed to shut Jet up.

As the tournament progressed, Team Heroes had their own fair share of losses, with Knuckles remaining seriously dedicated to the competition and his team. At the end of the tournament, all teams had an equal amount of victories and losses, and Knuckles and the other teams came to the awards ceremony to collect their price, but Eggman (as King Doc) made them have a final race against his ultimate Gear-jockey robot.

After the race, Eggman dropped his disguise and revealed that he used the World Grand Prix to get the riders' racing data with his E-10000 robots to create the ultimate Extreme Gear which he could use for his own agenda, which Knuckles knew confirmed his suspicion about E-10000E. Eggman then challenged Knuckles and the others to a race, but lost. As Knuckles then remarked the doctor's scheme had turned into a joke, Metal Sonic revealed himself as the one controlling E-10000B and passing fake data to Eggman, while taking the real data himself in an effort to beat Sonic in Extreme Gear riding.

Knuckles and the others following watched as Metal Sonic challenged Sonic to a race, in which Sonic defeated his robot copy. Afterwards, as the World Grand prix came to a close and everyone began to leave, Knuckles blamed Eggman for all the trouble they had to face during the tournament.

Sonic the Hedgehog (2006)
In Sonic the Hedgehog (2006), Knuckles saw Dr. Eggman on the outskirts of Soleanna. There, he received a message from Eggman, who told him to give it to Sonic. Passing on histhat he wanted to meet Sonic in the warehouse district of New City to Tails, Knuckles awaited Sonic's arrival. Eventually, Sonic got there, and Knuckles gave him Eggman's message. From the message, the trio learned that Eggman demanded the Chaos Emerald Sonic possessed in exchange for the return of Princess Elise, though Knuckles found it to be a cocky demand.

Despite the possibility that Eggman was setting up a trap, Knuckles followed Sonic and Tails to Eggman's base in White Acropolis. When they got there, Eggman remarked they were late, but Knuckles blamed Eggman's forces for that. As Sonic handed over the Chaos Emerald, Eggman double-crossed the trio and trapped them in a barrier that Knuckles tried unsuccessfully to punch through, and were send into an apocalyptic future by Eggman's machine. After a rough landing in the future on Knuckles' behalf, the group met Shadow and Rogue, who had been sent there by Mephiles. As they learned from Shadow and Rouge of where they were, Knuckles wondered how they could get home, and heard that Shadow planned to use Chaos Control to create a space-time rift, though it required lots of energy. The group therefore decided to work together to find the Chaos Emeralds needed for the travel.

As Knuckles, Sonic and Tails searched for the Chaos Emeralds, Knuckles was crestfallen to see nothing but ruins. Here, the group saw Silver and Blaze talking with Mephiles, who told them that Sonic was responsible for the devastation of this future and took them back in time to kill Sonic. After they left, Knuckles and the others learned from their database that Elise would die in the Egg Carrier's crash landing three days after Sonic met her.

After locating a Chaos Emerald in Flame Core, Knuckles and his group met up with Shadow and Rogue in that location. There, Rouge claimed herself a better treasure hunter than Knuckles for finding one Chaos Emerald, and Knuckles took it as a insult, before rebuffing it, and shortly after remarked to Rouge that she could stay behind while the got the Chaos Emerald. After making it to the central volcano, Knuckles and the others found a Chaos Emerald when Iblis attacked, but Sonic and Shadow defeated it. Sonic and Shadow then used the two Chaos Emeralds to trigger Chaos Control and created a time-space rift, and Knuckles returned to the present with Sonic and Tails, though Shadow and Rouge stayed behind.

Back in the present, Knuckles helped Sonic and Tails find information on Elise's whereabouts, before Sonic took off on his own to save Elise. Sometime afterwards, Knuckles helped Sonic getting through Aquatic Base so that Sonic could save Elise from Eggman and her imminent death onboard the Egg Carrier.

Later on, Knuckles passed through Castle Town with Tails and Amy when they were suddenly caught in a spatial distortion created by Solaris, who attempted to consume time itself. As a result, Knuckles and the others were send to the End of the World, where they met Shadow, Silver, Rouge, E-123 Omega and Eggman. There, they found Elise and Sonic, and Knuckles discovered much to his shock that Sonic was dead, having been killed as a part of Mephiles' plan to remake Solaris. As Solaris began to make his move, Knuckles opted to destroy him, but it was deemed impossible due to Solaris' temporal omnipresence and Sonic's passing. When Elise sensed that Sonic's soul was still among them however, Knuckles and the others headed out to collect the seven Chaos Emeralds in order to revive him, with Knuckles retrieving the cyan Chaos Emerald.

After collecting the Chaos Emeralds, Knuckles and the others witnessed Elise revive Sonic as Super Sonic, and Knuckles jumped in joy at Sonic's return. When Super Sonic then transformed Shadow and Silver into into Super Shadow and Super Silver, Knuckles stood behind and supported the three hedgehogs. As Solaris was defeated, Knuckles celebrated with Tails as they were engulfed in light. When Sonic and Elise then ensured that Solaris never came to exist, time was reverted, resulting in the events and memories of the adventure being erased and Knuckles to be returned to where he was prior to the events.

Sonic Rivals
In Sonic Rivals, Knuckles was guarding the Master Emerald when it suddenly disappeared right before his eyes. Determined to get it back, Knuckles searched for the Master Emerald and eventually arrived on the newly-appeared Onyx Island. While unable to find the Master Emerald there, Knuckles found the island familiar. Knuckles then saw who he believed to be Dr. Eggman, but was really Dr. Eggman Nega disguised as Dr. Eggman (Knuckles however, does not realize this throughout the game) with Sonic, and he suspected that the doctor stole the Master Emerald. Confronting Eggman Nega with his accusation, the doctor confessed it by showing that he had turned the Master Emerald into a card with his special camera. Meanwhile, Sonic asked Eggman Nega where Tails and Amy's where, and Eggman Nega showed that he had turned them into cards also. Eggman Nega then said that they had to catch him to get the cards back and escaped, and Knuckles competitively raced Sonic to the doctor.

After they found Eggman Nega, the doctor backed down on his words, much to Knuckles' annoyance and attacked them with the Egg Turtle. Though Knuckles and Sonic defeated it, Eggman Nega disappeared. Knuckles then found Shadow, who was looking for the doctor as well, and asked him if he had seen Eggman Nega, but was berated for letting Eggman Nega get away. Angered, Knuckles raced against Shadow to see who found Eggman Nega first. After reaching Eggman Nega, Knuckles demanded the Master Emerald back, but the doctor attacked him and Shadow in the Egg Falcon, which the two of them defeated.

After the battle, Knuckles almost got the Master Emerald card back from Eggman Nega when the doctor used it to teleport him to another area. There, Knuckles met Silver for the first time (since the events of Sonic the Hedgehog (2006) were negated), who had come to bring Eggman Nega back to the future. When Silver asked if he had seen Eggman Nega carry something, Knuckles told him about the doctor's camera, before asking Silver of who he was. Silver, however, did not want to waste time on him, which angered Knuckles and he chased after Silver. Eventually, Knuckles found Eggman Nega and asked him about how he made the Master Emerald disappear from Angel Island, and heard him say that Onyx Island was Angel Island, before being attacked by Metal Sonic. After beating Metal Sonic, Knuckles pondered fruitlessly about how Onyx Island could be Angel Island when he met Shadow. Knuckles asked Shadow if he had seen Eggman Nega, but was berated for letting the doctor get away again, and he competitively raced Shadow to Eggman Nega.

Knuckles and Shadow eventually found Eggman Nega. Knuckles questioned Eggman Nega about his earlier statement and heard him say that Onyx Island was Angel Island from the future, before being attacked by the Egg Lynx. After defeating the machine, Knuckles tried to make sense of what Eggman Nega said, but found it too confusing. Knuckles then met Sonic and Tails, and he realized that Sonic had beat him to Eggman. Not wanting Sonic to outdo him, Knuckles raced Sonic to Eggman Nega.

Knuckles eventually found Eggman Nega and demanded an explanation. Eggman Nega then revealed that the Master Emerald disappeared because he turned it into a card in the future, which due to the Master Emerald's properties made it disappear in all time frames, and that he then used it to transport the Angel Island in the future to the present as Onyx Island. Seeing that Eggman Nega was responsible for all this, Knuckles defeated both the Egg Kong and Metal Sonic. Frustrated at his constant defeats, Eggman Nega told Knuckles that he now planned to turn the world into a card that he could control as he wished and escaped, much to Knuckles' frustration. Sonic and Tails then showed up in the Tornado as they were heading to Eggman Nega’s base, and Knuckles teamed up with Sonic to stop Eggman Nega. As Knuckles and Sonic ventured through Eggman Nega’s base, Shadow and Silver also appeared. With each meeting, the rivals put aside their differences and teamed up with one another to help stop Eggman Nega, and Knuckles agreed to all their help.

At the center of the base, Knuckles and the others found a large spaceship with Eggman Nega’s special camera equipped on that he planned to use to turn the entire world into a card. Knuckles then noticed that Eggman Nega planned to fuel the device with the Master Emerald's card and some other cards he had taken, but the four rivals headed into battle and destroyed the spaceship as it took off, thus foiling Eggman Nega’s plan for good.

Having retrieved the Master Emerald at last, Knuckles planned to use its power to send Onyx Island back to the future where it belonged, and as well to begin looking for the other treasures Eggman Nega had trapped in his cards.

Sonic Rivals 2
In Sonic Rivals 2, Knuckles discovered that the Master Emerald was missing again, and began to search for it. As his search took him to an island, Knuckles suspected that Dr. Eggman had stolen it. There, he met Rouge, who offered to help look for the Master Emerald, but Knuckles was suspicious of her motives. Rouge then revealed that she needed help finding the Chaos Emeralds, but she would then take Knuckles to Eggman, and Knuckles agreed to help her. Knuckles then saw Sonic and Tails, who were also looking for Eggman, and was teased by Sonic for being on a date. Knuckles asked Sonic if he had seen Eggman and reluctantly explained why he needed to find him. When Sonic insisted on getting to Eggman first though, Knuckles raced and fought Sonic to find Eggman.

Knuckles and the others eventually found Dr. Eggman, who was really Eggman Nega masquerading as Dr. Eggman once more (and again, Knuckles does not realize this throughout the game). Knuckles demanded the Master Emerald back, but the doctor played innocent and attacked in his Egg Liner. After the fight, Knuckles and Rouge followed Eggman Nega to Sunset Forest Zone, where Rouge suggested that the doctor had to have an Emerald Detector to locate the Chaos Emeralds and Master Emerald. Trusting Rouge's words, the two of them left to find this device. On his own, Knuckles met Shadow and explained what he was doing. When Shadow then insisted to keep them from the Emeralds however, Knuckles fought Shadow to stop him.

Knuckles and Rouge eventually found Eggman Nega with Shadow and Metal Sonic. Hearing that Eggman Nega indeed had an Emerald Detector, Knuckles demanded the device as the doctor attacked them in the Egg Dealer. After defeating it, Knuckles and Rouge got the Emerald Detector, which soon after found a signal around some Chao. As Knuckles searched the area in Neon Palace Zone, he met Silver, who wanted the Chao, and Knuckles let him have them while he looked for Rings to re-energize the Emerald Detector. Afterwards, Knuckles asked Silver of why he sought Chao, but thought he was crazy when he heard it was to save the world, and they ended up fighting. Later on, Knuckles and Rouge found Eggman Nega with Silver and Espio, and he asked the doctor where to find the Master Emerald. Eggman Nega then attacked in the Egg Dealer, but the group defeated it.

Arriving in Frontier Canyon Zone, Knuckles and Rouge lost track of Eggman Nega. As Knuckles pondered about Silver's statement, the Emerald Detector found more Chaos Emeralds, but Knuckles was frustrated that it was not the Master Emerald. Knuckles then noticed Shadow and Metal Sonic nearby and followed them. Knuckles tried to question Metal Sonic, but ended up chasing after him after hearing Eggman's voice come from the robot. He briefly lost track of Metal Sonic, but met and fought him again when he gathered Rings for the Emerald Detector. Shortly after, Knuckles met Rouge, and learned from her that Eggman Nega sought to bring forth the Ifrit and destroy the world. Just then, Eggman Nega attacked them in the Egg Bull, but Knuckles and Rouge defeated it despite inference from Shadow and Metal Sonic.

Getting to Mystic Haunt Zone, Knuckles asked Rouge why came were here, and was convinced by Rouge that Eggman was here, instead of her client that had assigned her to collect the Emeralds. While looking, Knuckles met Espio and asked him if he had seen Eggman or Shadow, believing one of them had the Master Emerald, but was dismissed. Soon after, Knuckles met Metal Sonic and fought him so he would bring him to Eggman. Afterwards, Knuckles found Eggman Nega and Shadow and demanded the Master Emerald back. As Eggman revealed that he used Rouge to collect all the Chaos Emeralds, which were needed to open the portal to the Ifrit's dimension, and Silver came, Knuckles had enough and fought the Egg Phantom.

After the battle, Knuckles saw that the portal to the Ifrit's dimension was opening, despite Rouge only having six Chaos Emeralds with her (with the seventh unknown to them being inside Metal Sonic). Intending to stop the Ifrit, Knuckles dragged Rouge with him into the Ifrit's dimension. After entering, Knuckles lost track of Rouge and began to look for her, and soon after found the Ifrit, who had taken control of Rouge. With no choice, Knuckles faced both Rouge and the Ifrit. Despite Knuckles occasionally falling prey to the creature's mind control himself, the two of them managed to defeat the Ifrit, thus preventing it from leaving its world, and got back to their home dimension before the portal closed.

After checking up on Rouge, Knuckles was annoyed to not have found the Master Emerald, but then discovered to his frustration that it had been inside the Emerald Detector all along. As Knuckles then received praise from Rouge on his heroism, he saw Rouge escaping with the Master Emerald, and he chased after her.

Sonic Chronicles: The Dark Brotherhood
In the beginning of Sonic Chronicles: The Dark Brotherhood, Knuckles, Sonic, Tails and Amy faced Dr. Eggman on the Egg Carrier, and successfully made the flying vessel crash into Metropolis while Eggman was presumed dead in the crash.

Some time later, Knuckles learned that six of the Chaos Emeralds had been stolen by a group dubbed the Marauders. Intending to stop these thieves, Knuckles came to Tails and had him help set up a trap for the Marauders by using the last Chaos Emerald as bait. When the Marauders appeared, however, they jammed the trap and turned on Knuckles. Despite fighting back, Knuckles was overwhelmed by sheer numbers and was defeated by their leader, Shade, for then to be taken with them as they escaped with the Chaos Emerald.

Knuckles was afterwards locked up in their hideout in Mystic Ruins. When he attempted to break out on his own, he met Sonic, Tails, Amy and their other friends, who had come to rescue him. No sooner though, as Knuckles decided to head back to Angel Island to protect the Master Emerald from the Marauders, they discovered that the island was gone. Suspecting that Eggman was behind it due to the Marauders using Eggman’s robots, Knuckles and the group began looking for the doctor using Tails' Eggman Detector. After finding five Eggman Devices, Tails made a Pattern Generator that the team used to unlock Eggman's hideout in Green Hill Zone. Upon finding him however, they discovered that Eggman was against the Marauders as well and claimed to be reformed, which Knuckles believed. Willing to help fight the Marauders, Eggman offered to lead Knuckles and the other into Metropolis where the hijackers of Angel Island, the Marauders, had drawn it to with the Chaos Emeralds, which they accepted.

After arriving in Blue Ridge Zone, Knuckles and the others met Shade and her lackeys, and Knuckles discovered to his disbelief that Shade and the Marauders were a group of echidnas called the Nocturnus Clan, exiled to the Twilight Cage in ancient times. After defeating them, Shade blocked their way to Metropolis, but Knuckles and the others managed to find a way around it. Knuckles, meanwhile, was upset to finally meet others of his kind, but was forced to fight them. Regardless, he stood by his duty and was cheered up by Sonic. Despite wanting to go alone, Knuckles was joined by Sonic and his party as he went to Angel Island to prevent the Nocturnus Clan from taking the Master Emerald, while Tails and Eggman prepared a weapon against the Nocturnus Clan.

After hijacking one of the Nocturnus Clan's airships and getting some help from Tails' team, Knuckles, Sonic and their group made it to Angel Island. There, they met the Nocturnus Clan’s leader, Imperator Pir'Oth Ix, who sought to rule the world, which shocked Shade, who just wanted to leave the Twilight Cage. As Ix's released his soldiers on them, Knuckles began to lose hope, but was urged on to keep fighting by Sonic until Tails and Eggman had the weapon ready. When they were wearing down, Tails and Eggman deployed the weapon, which dispatched the soldiers, thus saving Knuckles and Sonic. As the united group fought Ix, the Noturnus Clan leader blasted everyone anyway, even Shade for voicing her disapproval, but Knuckles saved her before she fell off Angel Island. After Ix then stole the Master Emerald, he used it to create a wormhole into Knuckles' dimension so that the Nocturnus Clan could conquer it, and Angel Island fell from the sky. With the Nocturnus Clan possessing all the emeralds, Knuckles despaired, but the team then came up with the plan of going after Ix into the Twilight Cage and reclaim the Emeralds, and Shade joined Knuckles and their team to stop Ix.

After the team restored the Power grid and retrieved the Dimensional Buffer, Tails and Eggman constructed the Cyclone, which Knuckles and the others used it to enter the Twilight Cage, while Eggman stayed behind to watch the entrance portal. After entering the Twilight Cage, the team crash landed on the Kron Colony. There, Knuckles and the team succeeded in freeing the Kron from the Nocturnus Clan, thus gaining the Krons' support and reclaimed a Chaos Emerald. Afterwards, the team arrived on the N'rrgal Colony, where the N'rrgal Queen forced Knuckles and the others to retrieve the Chaos Emerald from the N'rrgals' enemies, the Zoah. On the Zoah Colony, Knuckles and the team got both the Zoahs' Chaos Emerald and the Zoahs' allegiance as well. The team then returned to the N'rrgal Colony and received their Chaos Emerald as thanks and got them as allies also. On Voxai Colony Alpha and Voxai Colony Beta, the team was pitted against the powermad Overmind, and Knuckles was briefly forced to serve them, but was freed thanks to Sonic. Together, the team then defeated the Overmind, thus gaining two Chaos Emeralds.

When the team planned to invade Nocturne to get the last Emeralds, Knuckles remained reluctant to fight Ix, fearing it could be a mistake. Instead, Knuckles hoped they could somehow return the echidnas to the world peacefully so that he would not be alone anymore, and tried to suggest an alternative to Sonic, though he still wanted to save Earth. After the team got all the alien races in the Twilight Cage to assist them, Knuckles and the others infiltrated Nocturne. Once there, Knuckles got the team split into two, with him and Shade leading their group and Sonic and Tails leading the other, to find the last two Chaos Emeralds, which Charyb and Scylla possessed.

After the other team left, Knuckles told Shade that he split them up so that he could attempt to redeem Ix and bring the echidnas back to the world, before Sonic could get to Ix. Not long after, Knuckles and his team were almost defeated by some Gizoid Centurions, but were saved by Sonic and Tails. Knuckles and his team then found and defeated Scylla and got his Chaos Emerald, before helping Sonic's group defeat Charyb by draining him of the water that empowered him. Afterwards, Knuckles and his team were teleported to Ix, who revealed history of the Nocturnus Clan and tried to persuade Knuckles to join him by offering him a place with his people. Hearing Ix's power-mad speech, Knuckles realized that Ix was unredeemable, and declined, saying that his duty was to protect the Master Emerald and that he would help the Nocturnus Clan his own way, before fighting Ix. When Sonic then arrived and took over the fight, Knuckles reclaimed the Master Emerald, and then watched Sonic defeat Ix in his Super State by using the Chaos Emeralds to become Super Sonic.

With his final defeat, Ix started to close the wormhole out of the Twilight Cage, but Knuckles and the others managed to get through it just in time. When they returned home however, Knuckles and the others saw that much time had passed, thus allowing Eggman to rebuild his forces, which they faced upon exit from the Twilight Cage.

Sonic Colors
In the Nintendo DS version of Sonic Colors, Knuckles got a letter from supposedly Dr. Eggman. Because of the letter's contents, Knuckles traveled to Dr. Eggman's Incredible Interstellar Amusement Park, though at some point after arriving there, he realized that he had tricked into coming there.

In Starlight Carnival, Knuckles came across Orbot and Cubot. Believing that they had cheated him to come here, Knuckles began fighting them. Just then, Knuckles got distracted when he noticed that Sonic and Tails were there, allowing Orbot and Cubot to get away. When Sonic asked Knuckles of why he was here, Knuckles tried to pretend that he was out for a scroll. However, Sonic thought Eggman had tricked him again, but Knuckles told him to shut up, and challenged him to a race through a ride. After clearing the mission, which Knuckles lost, Knuckles moped about his defeat, until Sonic and Tails began asking him how of he got tricked into coming, but Knuckles denied several times that he was not tricked. If the player manages to clear the mission with an S Rank, Knuckles took his defeat more sportily, though he pretended that that he was not trying to win.

Sometime later, Knuckles met Rouge in Starlight Carnival, and he suspected that she was after the Master Emerald again. When Rouge teased him by saying that she might be, Knuckles insisted that he would stop her, causing their arguing to grow more heated. No sooner, Sonic and Tails arrived and tried to break up their argument, but Knuckles told them to stay out of it, believing firmly that Rouge was up to no good. Rouge then noted Knuckles' history of being tricked, but Knuckles denied that he was tricked into coming to there, and that he came on his own. Noticing that Rouge was trying to tell him something and that she knew about the letter he had received, Knuckles heard from Rouge that she was the one who wrote the letter. As Rouge then left, Knuckles was left very humiliated, with the situation not being made any better by Sonic who told him that he was at least not tricked by Eggman this time.

Sonic Generations
In the console/PC version of Sonic Generations, Knuckles attended and helped preparing Sonic's surprise birthday party. When Sonic arrived, Knuckles and the rest welcomed him. As the party began, Knuckles started conversing with Rouge when the suddenly Time Eater appeared. Knuckles was then sucked into one of the Time Eater's Time Holes and ended up at Sky Sanctuary in the White Space, where he was turned into a colorless statue due to the Time Eater's effects.

Eventually, Knuckles was returned to normal by Classic Sonic (Sonic's past self) and Modern Sonic (Sonic's present self). In the scenario where Classic Sonic rescues him, Knuckles, after realizing he was back to normal, thanked Classic Sonic and told him that he did a good job, before asking him if he had gained weight. In the scenario where Modern Sonic rescues him, Knuckles, after realizing he was back to normal, Knuckles thanked Modern Sonic for his help, though he remarked that he did not need it, and stated that it was good to have his sanctuary back.

When Classic and Modern Sonic confronted the Time Eater, which was revealed to be controlled by Modern Eggman and Classic Eggman, Knuckles arrived at the battle with the others and cheered on both Sonics, allowing them both to transform into Super Sonic. When the Sonics defeated the Time Eater, Knuckles and the others were sent back to the present, where Knuckles admitted to Sonic that he was not half-bad, only to be knocked into a tree by Amy for thinking so little of him. Continuing the celebration where it left off, Knuckles continued talking with Rouge, and later waved goodbye to Classic Sonic and Classic Tails when they returned to their own time.

Sonic Lost World
In Sonic Lost World, Knuckles remained behind with Amy to look after some animals while Sonic and Tails went after Dr. Eggman to free the other animals Eggman had captured. As Knuckles attempted to keep the animals calm, Amy contacted Sonic and Tails on the Lost Hex to hear the status on their rescue mission. Hearing they only managed to get one capsule of animals back, Knuckles deemed their effort and boasted over the Miles Electric that he would have gotten all the animals back, before he was pushed away by Amy and carried away by the animals.

When the Deadly Six took control of Eggman's Extractor and began draining the life out of Earth and everyone on it, Knuckles stood by and observed how energy of the planet was being taken away. Eventually, Knuckles himself became drained of his energy to the point where his death seemed imminent. Fortunately, Knuckles and everyone else were saved when Sonic defeated both the Deadly Six and Eggman, and Tails reprogrammed the Extractor to return the world's stolen energy. As Knuckles celebrated the world's restoration with Amy and the animals, Sonic and Tails returned, and Knuckles boasted to them that he would have finished it sooner, but accepted the outcome nonetheless, before watching Sonic try to take a nap.

Sonic and the Secret Rings
In Sonic and the Secret Rings, Knuckles took on the persona of Sinbad the Sailor from Arabian Nights. He is sought out by Sonic and Shahra as they need his help to stop the Ifrit Golem, one of the Erazor Djinn monsters. After freeing him from his prison, he tells them they can use his water blue World Ring to weaken the Ifrit Golem, but they had to take it back of the band of pirates who stole it from him. He is last seen following Sonic on his last adventures through the Arabian Nights as Sonic sought out a way to return home. He also appeared as a playable character in Party Mode.

Sonic and the Black Knight
Knuckles is in Sonic & the Black Knight. He is portrayed as Sir Gawain of the Knights of the Round Table, and uses the Galatine, two swords. He is guarding the cave when Sonic approaches him. Gawain thinks he is stealing the Dragon's treasure and attacks. After being defeated, he attempts suicide to avenge his honor since he failed his king's orders, but Sonic asks him if there is more to being a Knight than serving a king. He later helps with stopping Merlina's corruption of the Kingdom. Other than looking like Knuckles, Sir Gawain seems quite gullible like Knuckles originally was, and defends the dragon's treasure, a parallel to Knuckles because he defends the Master Emerald. His Soul Surge is Gail Meteor.

Mario & Sonic Series
Knuckles also appears in the game Mario and Sonic at the Winter Olympic Games. In the game he is a power-type character. His main rival is Wario. Knuckles signature move is the Screw Driver on the Wii and Spiral Uppercut for the DS version.

In Mario and Sonic at the olympic games, he has five missions and boss fight with Wario in Dream boxing. Missions are:
 * Throw three times increasing your distance with each throw in Hammer throw
 * Finish in 2nd place in 400m
 * Perform GREAT or PERFECT in all aspects of 10m platform
 * Perform 5 successful smashes and win in table tennis
 * Perform one combo within 30 seconds in Dream basketball

Sega Superstars Tennis
He also makes a cameo appearance in Sega Superstars Tennis in the Green Hill court, and in Super Smash Bros. Brawl (in the unlockable Green Hill Zone stage where he, Tails, and Silver run through the shuttle loop in the background).

Sonic &amp; Sega All-Stars Racing
Knuckles appears as a playable character in the racing game Sonic &amp; Sega All-Stars Racing. His All-Star Move is Emerald Power, which allows Knuckles to glide above the track and unleash an earthquake that stuns all opponents.

In the console versions, Knuckles is playable from the start, but in the DS and iOS versions, the user needs to pay 500,000 SEGA miles to play as him.

Sonic & All-Stars Racing Transformed
He returns as a racer once again in Sonic & All-Stars Racing Transformed, though he's changed his quad for a strange backward trike influenced by himself in this game.

Archie Comics
As in the games, the Archie Comics version of Knuckles is the guardian of the Master Emerald. However, in the Archie Comics, he is actually the latest in a long line of Guardians, collectively known as the Brotherhood of Guardians.

In the Archie Comics, the echidnas eventually returned from their mysterious disappearance, and Knuckles was reunited not only with his people but his large family as well.

Knuckles has many enemies in this continuity, including the echidnas of the Dark Legion and the super-powerful Enerjak (an identity he was once brainwashed into assuming himself). He also has a long-standing love interest in the form of a former Dark Legionnaire Julie-Su, and the two of them have a daughter named Lara-Su in various alternate futures.

Many echidnas believe that Knuckles is a legendary Avatar, destined to deliver the world from suffering.

Sonic the Comic
In the UK publication Sonic the Comic, Knuckles is not only the guardian of the Master Emerald but the Chaos Emeralds and the Floating Island as well. Although he was duped by Doctor Robotnik during the comics adaptation of Sonic the Hedgehog 3, he remained skeptical enough to conceal the fact that he possessed the Grey Emerald, which could control the other Emeralds and which he eventually used to defeat Robotnik after being betrayed.

His uncertainty of the fate of his own people greatly affected him, even more so when the only other echidna he met (Doctor Zachary) proved to be a genocidal madman.

In this continuity, Knuckles was in fact over 8000 years old and had been the leader of the echidna armies under Pochacamac, fighting the Drakon Empire. However, he retained no memory of this, having presumably survived to the present day by being in suspended animation.

Sonic X
Knuckles appears in the anime series, Sonic X. Like his game counterpart, Knuckles has been tricked by Doctor Eggman a few times throughout the series.

Sonic Boom
Knuckles will appear as one of the main characters in the new upcoming CGI animated TV series, Sonic Boom, which will air in Fall 2014.

Personality
Knuckles is independent, wild, tough and a loner by nature. Like how Sonic embodies the wind, Knuckles embodies the mountain; stern, unmovable and anchored to his duty. Due to having lived in seclusion on the isolated Angel Island and protecting the Master Emerald for most of his life, Knuckles is a rather antisocial and reclusive individual. As such, he cares very little about what others thinks, which makes him bluntly honest, straight forward and egotistical.

Knuckles is fiercely loyal to his homeland, and does whatever is in his power to protect it. He prefers to stay close to the island's current emerald shrine to keep a watchful eye over everything on his home in order to maintain peace. Despite this devotion, Knuckles is willing to go with his friends on their adventures whenever his help is needed, or when he feels the Master Emerald and Angel Island will be safe. Though Knuckles has found other lifestyles appealing, he will never trade away his duties as he is far too devoted to his role as guardian. When he is not focusing on his duty, Knuckles spends his time practicing his fighting skills, going treasure hunting or sometimes go hanging out with his friends

Knuckles is most of the time very serious, earnest and usually likes to be by himself. He is likewise stubborn, headstrong and inflexible, prefering to do things his own way and stands by his choices, which causes him to clash with others. Regardless, he is very strong-willed, seldomly wavering in his determination.

Though he is cool and determined in battle, Knuckles has an extremely short temper and aggressive behaivor, and is difficult to talk to or reason with when he is angry. Though his wild-temper has often been known to get him into trouble, Knuckles has also learned to use it to his advantage by channeling it into fighting whoever might be threatening his friends or his home.

Despite being a loner, his temper and tough facade, Knuckles is heroic, brave and kind-hearted, being willing to help others in trouble, even when they are his enemies or people he does not like, such as when he saved Rouge and Shade's lives when they at their respective times were his enemies. He is likewise a loyal and caring friend, who is always willing to help out his friends in tight situations.

Since meeting with Sonic, Knuckles has had a strong rivalry with him. The two of them were initially enemies, due to Eggman's trickery, but after Knuckles realized the truth, he and Sonic came to have a more friendly relationship. Despite this, however, Knuckles still held an inhospitable attitude towards Sonic, due to their different points of view and natures. This however stem from the fact that Knuckles is sometimes jealous of Sonic's independent nature and freedom, finding it enviable, though he would never admit it.

Having been living much of his life in isolation, Knuckles grew up believing in honesty, and holds a strong and steadfast belief that there is good in everyone, which always lets him give people (especially Eggman) second chances. Because of his lack of social ingenuity, however, it makes him very naive, extremely gullible and easily misled, which has given him a history of being tricked by Eggman. As such, Knuckles displays a distrusting and aggressive demeanor towards strangers and people he thinks has questionable motives. Over time, however, Knuckles has gotten better about this and is more suspicious concerning Eggman's trickery. Once he finds out he has been tricked, Knuckles can get quite angered, but quickly regains enough of his composure to immediately start working towards a resolution and will stop at nothing to punish the perpetrator.

Knuckles is rather simple-minded, but not dull-witted. He is prone to rash and ill-advised actions, especially when angry, and is not the one to pick complex strategies. Instead, he often chooses force to be the solution, pushing himself through obstacles while focusing on his original goal and ignoring all other factors along the way. When in his right element, however, Knuckles can be quite clever and sneaky, such as setting several successful traps for Sonic and Tails on Angel Island when they first arrived.

Knuckles is said to be shy around women in his bio in Sonic Jam, which makes him act awkwardly around girls like Amy, Blaze, and Rouge.

Because of his secluded lifestyle on Angel Island, Knuckles feels very uncomfortable in industrialized or crowded cities and places, and being around hi-tech objects or gadgets (mostly because he's not inclined).

Knuckles seems to have matured somewhat in Sonic Generations. While he still displays some aggressive, headstrong and stubborn behavior, he is shown being better to acknowledge his shortcomings and displays more personal restraint and better social interaction.

Strength
Knuckles's trademark ability is his immense amounts of superhuman physical strength, so vast that it enables him to accomplish incredible feats, such as shattering boulders to smithereens, punch holes through thick steel and lift objects several times his own size and weight. His super strength seems to lie in his upper body, particularly in his arms and hands. Knuckles' strength is believed to be equal to Sonic's mundane speed (Mach 1), which would make him able to lift and press 100 metric tons, making him physically stronger than all other characters in the series.

Another testament to Knuckles' monstrous brute strength is that he is able to strike out with his fists or throw object through air with such force that he can make them ignite fire and punch the ground with enough strength to cause fissures, tremors, explosions even kick up small volcanic eruptions over a wide area. He can even strike with such force that it causes the friction in the air to create explosions with enormous power.

Physical Abilities
Like most other character in the series, Knuckles is shown to be very fast on his feet, being able to run at remarkable, near-superhuman speeds, though he still not quite as fast as Sonic, Tails or Shadow. Additionally, his high speed does not seem to extend to his upper body, and he has been noted for having slow movements in combat. Over time, Knuckles began to lose some of his speed, but also gain a lot more power.

Knuckles also possess near-maximized physical endurance to match his strength, and is capable of taking as much major punishment as he is able to deal out, even being able to survive a bomb exploding right in front of him. Knuckles is as well strong enough to hold out against an army of robots without rest.

Unlike Sonic, Knuckles is a very experienced swimmer, due to his interest of being a treasure hunter, and can swim to incredible depths and with both great speed and skill.

Knuckles is also shown to have sharp reflexes and acrobatic skills, being able to do special tricks and movements while in mid-air, though he is not nearly as acrobatic as Sonic or Shadow are, nor can he jump very high. To make up for his lack of agility, however, Knuckles possesses a wide range of movement abilities. By stretching his arms and legs outwards while airborne, Knuckles can catch the wind under his dreadlock-like spines, allowing him to glide long distances through mid-air and can do so with great control over his movements. Also, by using the spikes on his fists, Knuckles can attach himself to walls and climb up any kind of surface with ease, no matter the material.

Knuckles is also a proficient burrower, able to dig into any wall or floor and excels at tunneling through subterranean regions with great speed.

Knuckles also the uncanny ability to sense the Chaos Energy of the Chaos Emeralds from a distance, or objects similar to them, such as the Sol Emeralds. Like Sonic and Shadow, Knuckles can also harness the power of the Chaos Emeralds to empower himself.

Combat Skills
Being the guardian of the Master Emerald, Knuckles is a very powerful and fierce fighter. He is a master of a wide variety of martial arts, focusing on hand-to-hand combat, and is capable of taking on even the most powerful of opponents without rest, such as when he was able to take down several of the military trained Nocturnus Clan soldiers. Even more so, he has been able to fight Sonic the Hedgehog to a standstill on several occasions. Also, in Sonic Chronicles: The Dark Brotherhood, Tails notes that anyone capable of beating Knuckles in a fight must be very powerful and dangerous, a testament of his amazing fighting abilities.

Fighting Style
When in battle, Knuckles makes most use of his powerful arms and fists to take on his foes, with his specialty lying in punching moves where he uses his spiked fists to their fullest. In terms of fighting style, Knuckles' focuses specially on power, using strong and powerful punches, such as powerpacked jabs or piercing uppercuts, to deal damaging blows to his opponents. Once he catches an opponent in his combos, he keep them trapped by keeping up his strikes, not allowing his opponents a chance to counterattack. For stronger strikes, Knuckles tend to build up momentum with his fists by swinging them around, before hitting his opponent with full force. In his Major Eruption move in Sonic Battle, Knuckles takes advantage of his burrowing abilities, hiding underground and hitting opponents with an uppercut as he leaps out when his opponent least expects it.

Despite being a powerhouse in close combat, as stated by Sonic, most of Knuckles' fighting moves are slow and easy to read, making Knuckles more vulnerable to those who give themselves time to read his moves.

Techniques and Moves
Knuckles' various moves and techniques revolves around his trademark Punch Attack, where he attacks his opponents with various punching combos, including surrounding his fists with fire. His Spiral Upper allows him to strike foes above him with a spinning uppercut, and his Drill Claw sends him spiralling down on his foes from above. Similar to those, he also has his Screwdriver which allows him to home directly at his enemies. For wider impacts, Knuckles can use his Hammer Punch or Knuckle Slam to create wide tremors or explosions that effect everything within their effect range.

Knuckles has also been shown being able to use Sonic's trademark Spin Attack and Spin Dash to curl himself up and spin into a spiky ball when in motion that can damage, destroy or mow down many obstacles or foes or even burrow underground. He does, however, not use these moves or their variants, such as the Homing Attack, as often as Sonic and Shadow do.

When gliding, Knuckles can also use his Grinding Knuckles Attack in conjunction with his movements, using the spikes on his fists to damage any foes he comes into contact with during his descend. With his Maximum Heat Knuckles Attack, Knuckles glides through air at high speeds, destroying any foes within his attack range.

Miscellaneous Skills
Knuckles is expert treasure hunter, which is shown during his several hunts for Emerald Shards, and can be considered one of the best treasure hunters in the world, if not the best. While not exactly highly intelligent, Knuckles is well-versed in ancient cultures, ruins and legends, and is very knowledgeable on the subject, such as when he was able to translate the ancient texts at Gigan Rocks with little effort.

Knuckles is also one of the few who knows how to access and utilize the powers of the Master Emerald, allowing him to harness the powerful emerald's various abilities.

Knuckles has been shown to possess some mystical abilities of his own, possibly due to his close connection to the Master Emerald, such as in Sonic Battle, where Knuckles displays some limited geokinetic abilities, such as harnessing elemental earth energies to protect or heal himself, or calling forth meteor-like rocks from above to strike his opponents, which is described as "supernatural control of earth".

Knuckles has proven himself to be a skilled Extreme Gear in the Sonic Riders series, having shown himself a worthy competitor against many of the world's best Extreme Gear riders. To best put his skills in perspective, Knuckles was able to beat Storm the Albatross in a race, who is a part of the world's best Extreme Gear rider team, the Babylon Rogues. When riding his Extreme Gear at high speeds, Knuckles can bash his way through certain obstacles effortlessly, and, when someone gets near him on their Extreme Gear, he can engage in close combat with his opponents, without losing control over his Extreme Gear.

Transformations
Like Sonic and Shadow, Knuckles has the ability to power up into stronger forms of himself, usually by using Chaos Energy from the Chaos Emeralds and Super Emeralds. These transformations grants Knuckles overall improved physical abilities, such as greater strength and speed, and abilities he did not have access to before.

Super Knuckles
In Sonic & Knuckles and Sonic the Hedgehog 3 & Knuckles, with the seven Chaos Emeralds, Knuckles is able to become Super Knuckles. In this mode, Knuckles glows pink, as opposed to most other character's golden glow. When Knuckles is in his Super State, he gains invincibility and all his powers and natural abilities are enhanced up to their full limit. Super Knuckles is several times faster and more powerful, and can climb walls twice as fast and fly. He however needs rings to maintain this transformation.

Hyper Knuckles
In Sonic the Hedgehog 3 & Knuckles, Knuckles can also transform into an extended version of Super Knuckles, called Hyper Knuckles with the seven Super Emeralds. Unlike Hyper Sonic, who blinks multicolored, Knuckles blinks between bright and dark shades of Red and Pink. In this form Knuckles is faster and stronger than Super Knuckles and he can destroy all on-screen enemies by gliding into a wall, causing the stage to shake. He also have the ability to fly at a fast speed without staying in the air long enough to reach the speed when he is in normal form. Hyper Knuckles is also incapable of drowning. Like Hyper Sonic, Hyper Knuckles has an after image effect when moving.

Sonic the Hedgehog
Sonic is Knuckles's good friend and rival, They have known each other for a long time, but their relationship seems to be somewhat complicated. The two do not understand their differences and they often cause fights, Sonic being cool and cheeky and Knuckles being tough and serious. It is also mentioned in Sonic Heroes that Knuckles is somewhat jealous of Sonic's freedom and carefree attitude.

Knuckles is often tricked by Dr. Eggman into believing that Sonic is the bad guy. That causes them to get into fights and Sonic teases Knuckles whenever this happens, in which Knuckles does not take it very well. However, since then he has gotten better with this and is more aware of Dr. Eggman's plans. With Sonic's speed paralleling Knuckles' strength in every way, their fights are always climatic. (A similar rivalry is existent with Shadow in both Sonic and Knuckles, as all three have fought each other numerous times.)

The rivalry has all but disappeared in some continuities and in others it is a sort of game between the two, actually serving as the plot for the game Sonic Rivals, where Dr. Eggman (really Eggman Nega in disguise) captures Tails and the Master Emerald and turns them into cards. Knuckles tells Sonic that he must get to Eggman first and save the Master Emerald, so Sonic decides that they should race each other, which Knuckles agrees on.

Over time, Knuckles' relationship with Sonic has improved and he has come to see Sonic as both a rival and one of his best friends (the other being Tails) and help each other in many situations. The two show teamwork in battle as seen in Sonic Heroes and in Sonic the Hedgehog (2006).

In Sonic Generations, it is shown that Knuckles is actually impressed by Sonic and has belief in his abilities, but does not directly want to admit it. This is shown when Knuckles responded, "Thanks for the help, not that I needed it!" after Modern Sonic saves Knuckles and also when Knuckles told Sonic when he was not "half bad" after fixing the time, beating Time Eater and saving his friends. If Classic Sonic saves him, then he compliments Sonic by responding, "Thanks Sonic, you did a good job back there", which implies that he will sometimes admit, although he also asked if Sonic gained weight.

Dr. Eggman
Knuckles is constantly tricked by Dr. Eggman. In Sonic 3, Eggman had tricked him saying that Sonic's the enemy who is stealing the Chaos Emeralds, and because of Knuckles' simplicity he had believed Eggman and played various tricks on Sonic as well as fighting him. Knuckles has also been tricked by Eggman in Sonic Advance 2. Knuckles was tricked by Eggman again in the TV show Sonic X, but as the games pass by, Knuckles has stopped falling for Eggman's tricks, as mentioned in the guide for Sonic Riders: Zero Gravity. Knuckles has also shown a rough attitude towards him in the Sonic Rivals series even once stating that he won't believe anything he says a twist to his former attitude against him and something even Eggman is taken aback from.

Rouge the Bat
Rouge the Bat is Knuckles' rival. Knuckles and Rouge have been fighting over the Master Emerald ever since the two met. Rouge was designed to be Knuckles' compatibility just like how Shadow was designed to be Sonic's compatibility when it comes to basic rivalry and skills.

In Sonic Adventure 2, when Knuckles purposely shatters the Master Emerald to save it from Dr. Eggman, Knuckles and Rouge both go looking for its pieces. Eventually, Knuckles has to hunt Rouge down for the remaining pieces, and the two have their final confrontation at the level, Meteor Herd. But during their fight, he saves her life instead after she slips on a narrow beam and was about to fall into a burning pit of lava. After the rescue, Rouge and Knuckles share a long moment gazing at each other, before Rouge snatches her hand away and retorts with ungratefulness and teasing. In the end, Rouge gives him the remaining pieces of the Master Emerald and stubbornly complains that, "They stink like echidnas do!". Knuckles gathers the shards to complete the Emerald and glances over to her, muttering, "I'm sorry if I hurt you...", and runs off. Before the scene fades out, Rouge gives a thoughtful smile over her shoulder before exiting.

In Sonic Heroes, at the end of Team Dark's story, Rouge commented that she would go look for the Master Emerald, "since that irritating echidna is here." However, in the last scene, she went to Knuckles and coquettishly hinted about going to look for someone else's treasure. Knuckles smiles and says "She never gives up, does she?"

In Sonic Chronicles: The Dark Brotherhood, codex states that, "there's a sort of unstated connection between Rouge and Knuckles that neither are overly willing to explore." Rouge even admits that Knuckles is cute but just not her type during the game.

In Sonic Rivals 2, the two are teamed up. Rouge's reason for this is because she had a mysterious client who told her that if she found all the Emeralds, she would be rewarded. She teamed up with Knuckles in search for the identity of her client. They fight the Ifrit to get back to normal depending on which side you play.

In Sonic the Hedgehog (2006), Rouge joins up with Knuckles to collect the 7 Chaos Emeralds to bring Sonic back to life.

In Sonic Colors, Knuckles explains to Rouge that he is at Starlight Carnival because he received an invitation from Dr. Eggman, but proving that he did not get tricked. Rouge tells him that the invitation was written by her, causing Knuckles to burst in anger.

In Sonic Generations, Knuckles and Rouge oddly seem to be friendly to each other at the party, as they are seen setting the table, eating, smiling and talking to each other.

Friends/Allies

 * Sonic the Hedgehog (Best Friend, Rival)
 * Miles "Tails" Prower (Best Friend)
 * Amy Rose
 * Cream the Rabbit
 * Cheese the Chao
 * Vector the Crocodile
 * Espio the Chameleon
 * Charmy Bee
 * Blaze the Cat
 * Silver the Hedgehog
 * Shadow the Hedgehog
 * Rouge the Bat (also rival)

Rivals

 * Wario (in the Mario & Sonic series)
 * Rouge the Bat (friendly rival)
 * Blaze the Cat (formerly)
 * Sonic the Hedgehog (friendly rival)
 * Storm the Albatross (rival in strength)

Enemies

 * Doctor Eggman
 * Metal Sonic
 * Fang the Sniper

Trivia

 * According to the Sonic 3 manual, Knuckles' favorite food is grapes. This is referenced many times in the games.
 * In Sonic Generations, once the Sky Sanctuary and Knuckles are restored, you can see grapes growing on a tree behind Knuckles. This is an Easter Egg for Knuckles as grapes are his favorite food.
 * In Sonic and the Black Knight. Knuckles' counterpart, Gawain fights with two swords on both hands making him ambidextrous. This could mean that Knuckles might be ambidextrous as well.
 * Strangely, in Sonic 3, Sonic & Knuckles, and Sonic 3 & Knuckles, the cutscene Knuckles is slightly pinker than the playable Knuckles. This is due to the palettes conflicting with the HUD items, the playable Knuckles was able to be perfected so this would not happen.
 * Knuckles has been tricked six times all together in the TV shows he stars in. Twice in Sonic Underground, and four times in Sonic X.
 * In Sonic 3 & Knuckles, finishing the game with only the Chaos Emeralds leaves a picture of the character's Super State on the Game Select screen. If the game is completed with Knuckles, an image of Super Knuckles is shown. In this image, he appears to be the same color as Knuckles, but with a bright purple aura.
 * Due to space limitations, in Sonic Drift 2, Knuckles' name is spelled "Knucles".
 * In the Mega Drive games he is playable in, the letters K.T.E. (Knuckles the Echidna) are by his life icon, instead of "Knuckles" because the name display could not support more than than five letters, like on "Sonic" and "Tails".
 * Knuckles's eye color has varied in the Sonic series, changing from blue to purple. In Sonic Battle, he is actually portrayed with both eye colors (blue for the fighting and purple for the cutscenes.)
 * He and Shadow were originally confirmed to appear in Sonic Unleashed.
 * Knuckles' music was one of the reasons for the "Mild Lyrics" warning in Sonic Adventure 2. "Unknown From M.E.", "Deeper" and "Kick the Rock!" were among them.
 * Knuckles and Amy are the only 2 Sonic characters who appeared to have "aged"; Knuckles going from 15 to 16, and Amy going from 8 to 12.
 * Knuckles, along with Sonic and Dr.Eggman are the only characters whose Japanese voice actors have voiced their character in all Sonic games since Sonic Adventure.
 * Knuckles is the only playable character in Sonic '06 who does not finish a level/boss/town mission. Despite this, Knuckles does have a victory pose. This can be seen if the player glitches the levels to the end with Knuckles, the victory pose is almost identical to his Sonic Adventure 2 victory pose.
 * During multiplayer on Sonic Heroes, the white crest symbol on Knuckles' chest will disappear while he is taunting the opponent.
 * In Sonic Rivals and Sonic Rivals 2, the player can unlock an Eggman costume for Knuckles.
 * Knuckles' socks have been miscolored five times:
 * In Sonic the Hedgehog 3, Sonic Triple Trouble and Sonic & Knuckles, Knuckles' socks were colored yellow during cutscenes as it interfered with the HUD palette.
 * And in Sonic Drift 2 and Sonic 3D Blast, Knuckles' socks were colored blue.
 * In a lot of the 2D games, the crest on Knuckles' chest is colored peach. But in later games, it's colored white.
 * Knuckles is the only character in the franchise with purple eyes.
 * One of Knuckles' nicknames is "Knuckle," as stated in the Japanese manual of Sonic 3.
 * In Sonic Battle, Sonic once calls Knuckles a "spiky-headed mole". This is a pun on how echidnas and moles have the same burrowing prowess. It is also be a play on the Japanese term for echidna, which literally translates as "needle-mole".
 * He is also mistakenly referred to as a mole in the Sonic OVA movie.
 * If the player pauses at the right moment, in Sonic the Hedgehog 3 or Sonic and Knuckles when the sign is twirling in the air, the Knuckles color will be blue instead of red.
 * Super Sonic is invincible to any damage, but somehow Knuckles knocked the Chaos Emeralds out of him in Sonic 3 & Knuckles. This indicates that Knuckles is powerful enough to knock him out of Super State.
 * In Sonic 3 and Knuckles, if one glitches Knuckles into Sonic's part of Marble Garden Zone Act 2, Tails will still fly him up so he can defeat Dr. Robotnik. It is the only time this can be done without a cheat.
 * In Sonic Colors, Knuckles is the only one of the "Side Quest" characters to have five poses. All the others have four.
 * Knuckles' crescent-shaped symbol on his body was originally going to be the NIKE logo on him as part of a short-lived sponsorship deal.

Solo

 * Knuckles has his own percussion theme in Sonic 3 & Knuckles.
 * In Sonic Adventure, Knuckles' theme song is called "Unknown From M.E." It is a mix of hip-hop, jazz, pop, and R&B. This song was performed by Marlon Saunders and Dred Foxx. This theme also appeared in Sonic and the Black Knight when Sir Gawain appears and when the Medal Of Gawain item is equipped.
 * In Sonic Adventure 2, Knuckles' theme song is also known as "Unknown From M.E." but has a faster pace and a greater focus on pure rap, and performed by Marlon Saunders and Hunnid-P.

Shared

 * In Sonic Heroes, Knuckles' team, Team Sonic, theme tune is called "We Can," and actively mentions him in the lines; 'And Knuckles by our side, makes this a safer ride.'
 * In Sonic Riders, Knuckles' theme, shared with Sonic and Tails, is an instrumental called "High Flying Groove."

Memorable quotes

 * "Still got it!" - Winning in Sonic Rivals 2.
 * "Ah finally..." - Restoring the Master Emerald in Sonic Adventure 2.
 * "As far back as I can remember, I've been living here on this dark island... Always guarding the Master Emerald from anything that could harm it. I don't know why I was given this job... Why it was my fate... Destined to be here... forever!" - Knuckles thinking about his life at the beginning of his story in Sonic Adventure.
 * "The servers are the seven Chaos. Chaos is power. Power is enriched by the heart. The controller is the one who unifies the chaos. Only you can do this. STOP THE CHAOS EMERALDS!" - Knuckles pleading with the Master Emerald to neutralize the power of the Chaos Emeralds in Sonic Adventure 2.
 * "It's closer..." - When the Emerald Radar turns red.
 * "I found 'em!" - When finding the three pieces of the Master Emerald in Sonic Adventure 2.
 * "Yeah, I feel good!" - After getting a B Rank.
 * "What do you think you're doing Shadow!?" - Knuckles when Shadow destroys a G.U.N. robot or soldier in Shadow the Hedgehog.
 * "Me? My fists are my weapons of choice." - Knuckles saying that he would rather use his fists than a gun in Shadow the Hedgehog.
 * "Hey good going." - Knuckles when Shadow defeats a Black Arms alien in Shadow the Hedgehog.
 * "Hand it over Eggman. I'm losing my patience." - Knuckles demanding Eggman to give him the Emerald Detector in Sonic Rivals 2.
 * "No time for games..." - Knuckles when he is about to use a special attack in the 2-Player mode of Sonic Adventure 2.
 * "Get down!" - Knuckles after unleashing the Hammer Punch special attack in the 2-Player mode of Sonic Adventure 2.
 * "Take this!" - Knuckles after unleashing the Thunder Arrow special attack in the 2-Player mode of Sonic Adventure 2.
 * "Take that!" - Knuckles after unleashing the Power Flash special attack in the 2-Player mode of Sonic Adventure 2.
 * "Look who's calling who a thief." - While Eggman was stealing the Master Emerald and Rouge called him a thief in Sonic Adventure 2
 * "I will protect the Master Emerald." - When starting a multiplayer stage in Sonic Adventure 2.
 * "That's a good one, YOUR Emerald. Talking to you is a waste of time!" - Knuckles before his second fight with Rouge in Sonic Adventure 2
 * "Just enough to pass." - Getting an E Rank in Sonic Heroes.
 * "What a wild ride." - Going in circles in Sonic Heroes.
 * "I'm so ready..." - Knuckles while standing still for a while in Sonic Heroes.
 * "Time for a Knuckles sandwich!" - Knuckles taunting the opposing team in the minigames of 2P Battle mode of Sonic Heroes.
 * "Whew, that was pretty tough." - Knuckles when defeating Metal Overlord in Sonic Heroes
 * "Well if I can't convince them, then I'll just let my fist do the talking!" - Being the last one still on the field when facing Team Rose in Sonic Heroes
 * "No way!" - When Knuckles tries to dig on something like metal or steel in Sonic Adventure
 * "Did she say red mutt?" - After Wave calls him a red mutt before leaving with Storm on the Babylon Garden in Sonic Riders
 * "Stone Fists! - After wining a fight in Sonic Battle
 * "It's not me! Blame Sonic!" - When talking to Rouge in the Japanese version of Sonic Battle
 * "I feel some strange energy..." - While walking around in the Space Colony ARK right before Sonic Chaos Controls in front of him in Sonic Adventure 2.
 * "As much as I hate to admit it, I think Tails is right about this." - Knuckles after hearing Tails' plan to defeat Perfect Chaos by helping Sonic go Super in Sonic Adventure
 * "We've no time to waste. We've got to defeat it now!" - Knuckles' frustration with Solaris ready to consume time itself in Sonic the Hedgehog (2006).
 * "I'll probably be on this floating island forever. Guarding the Master Emerald, again. I may not know the whole story behind this. But perhaps it's better that way. I am at peace once more." - Knuckles thinking once again about his role as Guardian of the Master Emerald in the ending of his story in Sonic Adventure
 * "I'm unstoppable!" - When Knuckles speeds up in Mario & Sonic at the Olympic Winter Games on the Wii
 * "Don't get in my way!" - When starting a race in Sonic Riders: Zero Gravity
 * "Anytime! Babylon Rouges!" - When finding the Babylon Rouges in MeteoTech
 * "Let's go... Yah!!" - About to perform a Gravity Dive in Sonic Riders: Zero Gravity
 * "It's a pretty famous ruin among us treasure hunters." - Knuckles explaining the Gigan Rocks to Sonic, Tails, and Amy in Sonic Riders: Zero Gravity
 * "Stooop! I get it, okay?! It just floats and that's good enough﻿ for me!" - Knuckles asking Tails to stop explaining how an Extreme Gear floats in Sonic Riders
 * "I sure don't wanna fall off." - Knuckles when the player turns the camera too much in Sonic Adventure and Sonic Adventure DX.
 * "A trap!? What have you done Eggman!?" - Knuckles confronting Dr. Eggman at the top of Crimson Tower in Sonic Riders: Zero Gravity.
 * "Outta my way!" - When attacking in Sonic Riders and Sonic Riders: Zero Gravity.
 * "It's over..." - Knuckles after dying in Sonic Adventure 2.
 * "Yeah! This is perfect!" - After getting an A Rank.
 * "I am one with the Master Emerald" - Starting a treasure hunt on 2-Player mode of Sonic Adventure 2
 * "My emerald, my destiny" - Getting a piece of the emerald on 2-Player mode of Sonic Adventure.
 * "If that's what you thought, you should've given me them in the first place." Knuckles after Rouge gives him the pieces of the Master Emerald in Sonic Adventure 2.
 * "I didn't use all my strength!" when getting a D-rank in Sonic Heroes or getting 2 stars in Sonic and the Black Knight.
 * "Stop attacking the good guys!" Knuckles when Shadow destroys a G.U.N robot or soldier in Shadow the Hedgehog.
 * "I must...protect...the Master Emerald..." - Knuckles, after losing to Rouge in their first, and only, battle on the ARK, in Sonic Adventure 2.
 * "Alien Scum!" - Knuckles when Shadow defeats a Black Arms alien in Shadow the Hedgehog.
 * "Damn! A dead end! Looks like we have to take our chances with the tornado!" - Knuckles, after arriving to a tornado in Glyphic Canyon in Shadow the Hedgehog.
 * "Hmph. I'm just warming up!" - Sonic Heroes.
 * "Thanks, Sonic! You did a good job back there! Hey, did you gain weight?" - Knuckles after Classic Sonic rescues him at Sky Sanctuary in Sonic Generations.
 * "Thanks for the help. Not that I needed it! But it's good to have my sanctuary back." - Knuckles after Modern Sonic rescues him at Sky Sanctuary in Sonic Generations.
 * "I'll handle the treasure hunting!" - Knuckles before the Sky Sanctuary mission with Modern Sonic begins.
 * "Come on Sonic, smack him!" - Knuckles cheering Sonic to keep going in Sonic Generations.
 * "Help! We're being sucked in!" - Knuckles when he gets sucked into the tornado in Shadow the Hedgehog.
 * "Yeah, that's what I'm talkin' about!" - When Knuckles wins a world tour event in Sonic and All-Stars Racing Transformed.
 * "How long are they going to make us wait? All this pent up energy is making me itch." - Knuckles in Sonic Free Riders.