Knuckles the Echidna (ナックルズ・ザ・エキドゥナ Nakkuruzu za Ekiduna?) is one of the main characters from the Sonic the Hedgehog series. He is an anthropomorphic echidna and the current guardian of the Master Emerald, a powerful ancient relic which is his solemn duty to protect from anyone seeking to abuse it. He is also the sole surviving descendant of the echidna race from the Knuckles Clan. His dominant traits are his super strength and the two spike-like knuckles on each of his gloves, from which his name is derived from, which he can use to dig with and climb walls. 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 entirely devoted to his duty, spending most of his time on Angel Island protecting the Master Emerald, and rarely cares for anything that is of no importance. 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 a faithful and good-hearted hero. He is also one of Sonic the Hedgehog's oldest friends and rivals.
Concept and creation
Knuckles was created and designed by Takashi 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 and usage of the market research about American kids’ taste. There were eight different candidates with the most popular one being Knuckles with his dreadlocks. One design even planned Knuckles to be more “reptilian”, like a dinosaur due to the popularity of Jurassic Park at the time. Knuckles' long tail in the final design is stated being a remnant from his early, more dinosaur-looking design. When it came to Knuckles' primary color, red and green were proposed candidates among the staff, while Yuji Naka was pushing towards purple. However, after conducting research on American children, it was revealed that red was overwhelmingly popular, thus being chosen for the character's color. The emphasis of the character was to break walls. He was initially meant to speak with a Jamaican accent.
Character designer Takashi Yuda never intended him to be any more than a "supporting character." Knuckles was introduced in Sonic the Hedgehog 3 as an "intimidator" because of his powerful abilities. He was given a headlining role in the next game, Sonic & Knuckles.
Knuckles is an anthropomorphic echidna with red fur that covers most of his body, a black nose on his peach-skinned muzzle, a white crescent-shaped patch of fur on his chest, and violet eyes. He also has seven dreadlock-like spines around the sides and back of his head and a medium-sized, tri-crooked tail.
In his younger years, Knuckles had black eyes, a more protruding chest, more defined cheekbones, and was shorter in height, but he has since grown out of these traits.
For attire, Knuckles wears red and yellow shoes, each with green cuffs, light gray soles, and a gray, hextuple-bolted plate on top. He also wears large, white, mitten-like gloves with sock-like cuffs and two spiked knuckles on each hand.
In the Sonic Riders series, Knuckles wears purple and light gray goggles with dark gray straps around his neck, and high-top tennis shoes similar to his standard shoes. He also wears his standard gloves with a dark gray band around each wrist.
Knuckles is independent, wild, hot-blooded, 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 for most of his life, Knuckles is a rather antisocial and reclusive individual. As such, he cares very little about what others think, which makes him bluntly honest, straight-forward, and somewhat 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 at his home. Despite this devotion, Knuckles is willing to leave his duty 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 not performing his duties, Knuckles prefers spending his time practicing his fighting skills, going treasure hunting, or hanging out with his friends.
Knuckles is usually solemn, stoic, and collected, and usually likes to be by himself. He is likewise stubborn, headstrong, and inflexible, preferring to do things his way, which causes him to clash with others. Regardless, he is very strong-willed, seldom wavering in his determination and will not give up on his goals once he has set them. While he is cool and determined in battle, Knuckles has an extremely short and wild temper and is hard to reason with when he is angry. Though his temper has often been known to get him into trouble, Knuckles has also learned to use it to his advantage by channeling it into his fighting skills.
Despite being a silent loner, Knuckles is a heroic, brave, kind-hearted, and selfless soul. Unwilling to forgive people for their evil ways, he will risk his own life to save anyone or get them out of trouble, and shows empathy for people, even if they are a villain or enemy. He is likewise a loyal and caring friend, who is always willing to help his friends out in tight situations and will do anything to protect them. When not angered, Knuckles is pretty laid-back and never cracks under pressure. He can also be very understanding on the sly and does not take kindly to people who disrespect or hurt his friends, or innocents, in any way.
Having been living much of his life in isolation, Knuckles grew up believing in honesty and holds a firm and steadfast belief that there is good in everyone, which always lets him give people second chances. Because of his lack of social ingenuity, however, it makes him very naive, incredibly gullible, fast about forgiving people and easily misled, which has given him a history of being tricked by Eggman. This has made Knuckles aggressive and suspicious towards anyone he deems questionable. 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 start working towards a resolution immediately.
Though not dull-witted, Knuckles is often prone to rash and ill-advised actions. While not above picking complex strategies, Knuckles often chooses force to be the solution, pushing himself through obstacles while focusing on his goal and ignoring other factors along the way. Similarly, he can also be quite reckless when panicking about the Master Emerald, such being especially evident during the Space Colony ARK incident, where he ended up fighting Sonic for the controls of the Space Shuttle and causing it to crash land as well as abandoning his allies out of a panic due to the Master Emerald shards being lost to space from a collision with a meteor forcing the cargo bay to open. When in his right element however, Knuckles can be quite clever, sharp-witted and sneaky, such as setting several successful traps for Sonic and Tails on Angel Island when they first arrived. He is also capable of learning from his mistakes. Knuckles has also proven himself to have a high degree of leadership skills, most noticeably during his time as the commander of the Resistance. He is noted to be very charismatic with inspirational speeches, and he has a flair of daring plans that provided the Resistance with a much-needed offensive during the War to Take Back the Planet. However, for all his skills as a leader, Knuckles is still easily distracted and prefers to be out on the battlefield rather than in the command center.
Knuckles is said to be shy around women, 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 high-tech objects or gadgets (mostly because he's not inclined).
Knuckles seems to have lightened up on later adventures, such as the Time Eater incident and the Phantom Ruby incident. While he still sometimes displays a brooding, headstrong, and stubborn attitude, he is shown to be better at acknowledging his shortcomings and displays more personal restraint and better social interaction.
Powers and abilities
Being the guardian of the Master Emerald, Knuckles is a very powerful fighter. Said to be an unstoppable power in fights, he is capable of taking on even the most powerful of opponents without rest. He has even been able to fight figures like Sonic, Shadow, Silver, and Rouge to a standstill.
Knuckles' trademark ability is his superhuman strength. Said to possess lots of power, he is strong enough to pulverize massive boulders, punch through solid steel, and lift objects several times his size and weight with ease. By comparison, Knuckles' strength is stated to equal Sonic's speed; considering Sonic's measured footspeed, which is known to range between Mach 1-5, it would mean that Knuckles is capable of lifting 100-500 metric tons.[note 1] This makes Knuckles one of the physically strongest characters in the series. Knuckles' strength seems to lie in his upper body, particularly in his arms and fists, the latter of which are noted to be as hard as rocks. Another testament to Knuckles' strength is that by just punching the ground, he can create fissures, widespread tremors, and even powerful volcanic eruptions. Additionally, he can punch with his fists or throw objects through the air with such force that they ignite from friction. He can even launch punches with such force that they create explosions of enormous power. Despite his main strength lying in his upper body however, Knuckles' legs are quite powerful too, as he can jump several stories into the air from a standstill position.
Knuckles is able to run at breakneck speeds that almost match Sonic's, who can reach supersonic running speeds. He is even able to run fast enough to create afterimages of himself and scale vertical surfaces and ceilings. Even so, he is not quite as fast as Sonic at his maximum speed, as Knuckles is noted to run fairly slow by comparison. Knuckles is also fast enough to execute rapid punches in quick succession within a split-second, although he has been noted to have slow movements in combat.
Knuckles possesses near-maximized physical durability. Testaments to this include him surviving a bomb exploding right in front of him through sheer toughness, and him going through atmospheric entry and then landing on the ground unharmed. In addition, despite the force of the impacts his fists receive when punching at high forces, Knuckles is never phased by the recoil, regardless of what he hits or how hard he is hitting. Said to be quite athletic, Knuckles is also shown to have sharp reflexes and acrobatic skills, enough to let him do special tricks and movements while in mid-air, pull off various Spin Attack maneuvers at high speed, and grind along rails just as fast as Sonic while doing tricks and evading obstacles.
Unlike Sonic, Knuckles is a good swimmer, being able to swim into incredible depths and with both great speed and skill. Thanks to the spikes on his fists, Knuckles is also a skilled burrower, being able to dig like a gopher into any wall or floor and tunnel through subterranean regions at great speed. The spikes on his fists also make him a skilled climber, as they allow him to plant his fists into any surface and scale them. Also, by stretching his arms and legs outwards while airborne, Knuckles can catch the air under his dreadlock-like spines to let him ride on air currents for a short distance.
Knuckles possesses the uncanny ability to sense energy, specifically the energy produced by the Chaos Emeralds and the Master Emerald or energies similar to those, such as those contained in the Sol Emeralds. and can track down their "signals" like an Emerald Detector. Like Sonic and Shadow, Knuckles can also harness the power of the Chaos Emeralds to empower himself. Knuckles is also the only person alive who knows how to control the Master Emerald, which allows him to utilize the jewel's different powers or tap into its vast energies to empower himself. Other more mystical abilities Knuckles has exhibited include summoning lightning bolts, harnessing earth elementals to heal himself, and using the supernatural power of the earth to make rocks fall from the sky.
Knuckles is also able to perform the Spin Attack, a technique where he curls into a concussive ball or cutting disk and directs himself at his targets. With it, Knuckles can shred or burrow through just about any substance given enough speed. Adept in its usage, Knuckles can utilize several variants of the Spin Attack for both ground- and aerial maneuvers, including the Spin Dash, Spin Jump, and Homing Attack.
Even without his Spin Attack, Knuckles is a skilled hand-to-hand combatant. A master in a number of martial arts focusing on hand-to-hand combat, Knuckles makes use of his powerful fists to take on his foes, with his specialty lying in punching moves where he uses his spiked fists for devastating blows. In terms of fighting style, Knuckles focuses on power, using straight, repetitive and forceful punches, such as power-packed jabs or piercing uppercuts to deal critical blows to his opponents. For stronger strikes, Knuckles tends to build up momentum with his fists by swinging them around, before hitting his opponent in full force. By taking advantage of his burrowing abilities, Knuckles can even hide underground before hitting opponents with an uppercut from below when his opponent least expects it. Despite being a powerhouse however, most of Knuckles' fighting moves are slow and easy to read.
Being the guardian of Angel Island, Knuckles has vast knowledge of the island's various locations, which allowed him to place traps and obstacles to stop Sonic and Tails during the Angel Island incident. Similarly, he in an expert treasure hunter with infallible instincts (which are referred to as his "treasure sense"), and can be considered one of the best treasure hunters in the world, if not the best. He can even sense the presence of treasures nearby and can as well pick up its scent and sniff his way to it. Also, while not highly intelligent, Knuckles is well-versed in ancient cultures, ruins, and legends, such as when he was able to translate the ancient Babylonian texts at Gigan Rocks during the MeteorTech incident.
Knuckles is also a skilled Extreme Gear rider, having proven 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 regarded as a "wind master". When riding his Extreme Gear, Knuckles can bash his way through obstacles effortlessly and engage in close combat with his fellow racers without losing control. With his Extreme Gear, Knuckles can even enhance his physical abilities.
When it comes down to it, Knuckles is also shown to have very competent leadership skills. During the War to Take Back the Planet, he was able to lead the Resistance for several months against the Eggman Empire and even come up with war strategies of his own.
As seen during Dodon Pa's Grand Prix, Knuckles has excellent skills when it comes to driving and racing in racecars like the Land Breaker. Along those lines, Knuckles has also demonstrated some rudimentary piloting knowledge of more advanced crafts, having once piloted the Egg Saucer, and a Space Shuttle from Eggman's base to the Space Colony ARK (albeit in a more dangerous manner for half the journey due to panic over losing his Emerald Shards).
Although he prefers to let his fists do the talking, Knuckles has wielded a number of tools during his adventures, albeit never permanently. During the Emerl incident for example, he made use of deployable landmines, and amidst the Gemerl incident, he would wield his own version of the Piko Piko Hammer.
With the seven Chaos Emeralds, Knuckles is able to attain a Super State known as Super Knuckles. In this state, all of Knuckles' abilities far surpass his normal ones. In addition, he is able to fly and is virtually invulnerable. However, this transformation consumes a lot of energy and requires Rings to be maintained.
In Sonic the Hedgehog 3 & Knuckles, Knuckles can transform into an extended version of Super Knuckles, called Hyper Knuckles, with the seven Super Emeralds. This form basically shares the same abilities and powers as Super Knuckles but on an even higher level.
By harnessing different variants of Hyper-go-on from Wisps, Knuckles can use specific Color Powers to transform into a certain form, such as a drill, a laser or even a planet, each one possessing its own unique abilities. So far, Knuckles has been able to transform into the Cyan Laser, Yellow Drill, and Indigo Asteroid. However, these transformations require a steady supply of Hyper-go-on to be maintained.
Sonic the Hedgehog
Sonic the Hedgehog is Knuckles' rival and best friend. While they have known each other for a long time, their relationship is somewhat complicated, the two of them having been summed up as "best frenemies." When Knuckles first met Sonic, they two of them had the worst kind of encounter, with Knuckles trying to keep Sonic from stopping the Death Egg's re-launch after Dr. Robotnik had deceived him into thinking that Sonic was a thief seeking the Master Emerald. As such, they started off as adversaries. However, when the echidna discovered that Robotnik had tricked him, he joined forces with Sonic to keep Robotnik and his robots from stealing the Master Emerald. Afterward, they parted ways on good terms.
Because of their first impressions of each other and their personalities and competing feelings, Knuckles and Sonic were not initially "good friends" to begin with. In fact, Knuckles and Sonic are much like oil and water. While Knuckles exemplifies the mountain and is stern, serious and unmovable, Sonic exemplifies the wind and is laid-back, cool and free. As such, Knuckles and Sonic tend to argue a lot. They likewise share a competitive rivalry with each other and it usually comes to blows when they clash, although their confrontations have become less serious in recent times, and are now more of a form of slapstick between the two. With Knuckles' strength matching Sonic's speed perfectly, their fights are anything between climactic to just plain funny.
Knuckles sees himself as Sonic's rival, though it has been implied it is because he envies Sonic's free lifestyle and self-reliant nature. Being as egotistical as he is as well, Knuckles sees himself as Sonic's better, as seen during the Lost Hex incident where he claimed more than once that he could do better than Sonic on his adventure. Also, because of his short temper, Knuckles usually falls for Sonic's teasing and provocations directed at him, which causes him to lose his cool and get angry at the hedgehog. This tends to make Knuckles seek outright brawls with Sonic to put him in his place.
Due to his lack of social abilities in the past, Knuckles used to fall for Dr. Eggman's deceit very often, which, in turn, would be the cause of most of his confrontations with Sonic, although as time passed, Knuckles has generally become more aware of Eggman's plans and has stopped believing his claims regarding Sonic. When Knuckles discovers he has been deceived by Dr. Eggman, he usually tries to hide him embarrassment to Sonic, who in turn tends to chide him by calling him "Knuckle-head", a nickname that does not sit well with Knuckles.
In contrast to their differences, after having been on several adventures together, Knuckles and Sonic's relationship have improved, with Knuckles seeing Sonic more and more as his friend. Likewise, they have always rushed to each other's aid when they are in a pinch. The two of them are connected by a hot-blooded friendship and while they still argue and complain about each other from time to time, they are perfectly synchronized in the heat of action. Details aside, they also have a connection that lets them understand what is really important without saying anything to each other. In fact, when it all comes down to it, Knuckles can be considered Sonic's best friend next to Tails. It can even be argued that the two of them are as close to each other as Sonic and Tails are, as the nature of their rivalry/quarreling friendship lets them have a relationship that does not require any hesitation. Also, according to Tails, Sonic and Knuckles are "funny" together.
While Knuckles is impressed by Sonic's skills on some level and holds a steadfast belief in him, he prefers not to admit when he needs his help; as seen during the Time Eater incident, after Sonic restored Knuckles from a lifeless state, Knuckles thanked Sonic for his help before quickly stating that he did not need it. At the end of the same incident, Knuckles also begrudgingly admitted that Sonic was not "half-bad" after defeating the Time Eater, showcasing a reluctance to admit how well Sonic does. Despite it all though, Knuckles and Sonic deeply acknowledge each other. The two of them are also great and loyal teammates. In addition to Knuckles being a vital part of Sonic's team, the two of them have been called "Fighting Buddies" in Sonic Advance 3. Noticeably, when they do manage to work together, Knuckles and Sonic form an unstoppable team. Additionally, Knuckles is always happy to help out Sonic if it means scrambling Dr. Eggman's evil plans for world domination.
Miles "Tails" Prower
Miles "Tails" Prower is a close friend of Knuckles. Although they do not seem to have much of a relationship in the earlier games, when they first met, Knuckles and Tails were enemies, as Doctor Robotnik had tricked the echidna into believing Tails and Sonic were intruders seeking the Master Emerald for evil purposes, though they become friends when Knuckles discovers that Robotnik had lied to him.
Unlike with Sonic, Knuckles does not see Tails as his rival, and generally shows a more amicable attitude towards the fox as well, particularly compared to his interactions with Sonic and other characters, although Tails occasionally irritates Knuckles with his technobabble. Likewise, Knuckles seems to enjoy teasing Tails from time to time as well, such as when he scares Tails with the idea that they fought with Shadow's ghost just before entering Hang Castle. Despite this, Tails is probably Knuckles' best friend after Sonic, and the two have teamed up several times through the series.
Knuckles has also shown that he cares about Tails, having assured Tails he had nothing to worry about when the fox cub once grew worried about Eggman's plots in Sonic Heroes; in that same game, the two were also hanging out in the Tornado 2 at the very beginning, before reuniting with Sonic later on, and Knuckles even points out after the trio defeated the Egg Emperor at Dr. Eggman's Final Fortress that the hedgehog "wouldn't have had a chance" if "it wasn't for [them]".
In Sonic the Hedgehog (2006), Tails and Knuckles appear as Sonic's main allies during his story; the two are also seen cheering Sonic in his battle against Solaris, and celebrating together after Solaris' defeat.
In Sonic Rivals, after Sonic had rescued Tails at Death Yard Zone, Knuckles (who was on a quest of his own to recover the Master Emerald), was seemingly surprised and happy to see Tails free from the card containing him at the same time; Tails later aids Knuckles and Sonic reach Eggman Nega's stronghold, the Meteor Base Zone.
In Team Sonic Racing, Tails and Knuckles (alongside Sonic) are invited to participate on Dodon Pa's Grand Prix as a team. In this game, the two seem to get along as usual, although the echidna became somewhat distrustful of the fox when he discovers him speaking to Vector the Crocodile in private. This caused him warn Sonic later on that Tails was "being sneaky".
Although they are good friends, Tails and Knuckles have fought each other on a few occasions (almost always when Knuckles has been tricked by Dr. Eggman), but in the end, there are never any hard feelings between them.
Amy Rose has only been seen interacting with Knuckles on rare occasions, although they seem to have an awkward, yet at the same time, friendly relationship. Although the two do not interact much (if at all) in the earlier games, they do so more often in the later installments of the series. In Sonic Heroes, the two are on opposing sides; when playing as Team Sonic, at the beginning of the battle against Team Rose, Knuckles will taunt Sonic about Amy saying, "Have you been messing with that girl's heart again Sonic?" In Sonic Rush, Amy stops Knuckles from starting a fight with Blaze. In Sonic Forces, they work together as part of the Resistance. Although they get along well in this game, Amy has to keep Knuckles in check at times, especially when Knuckles was more than willing to do the distraction at Green Hill himself, with Amy then saying that as the commander of the Resistance, he needs to stay at the Resistance HQ.
Knuckles is Dr. Eggman's third most formidable foe after Sonic and Tails, thwarting his plans most of the time, although, as stated before, due to his gullible nature, the echidna has also been the target of constant deception by the mad scientist, particularly in the past. As the games pass by, however, Knuckles has generally become more aware of Dr. Eggman's plans, as mentioned in the manual for Sonic Riders: Zero Gravity.
Knuckles has also shown a rough attitude towards the doctor in more recent titles, such as the Sonic Rivals series, even once stating that he will not believe anything he says, a twist to his former attitude against him and something even Eggman is taken aback from.
Shadow the Hedgehog
Knuckles and Shadow do not have much interaction with each other, but when they do, they are either allies or rivals. He and Knuckles started off as enemies in Sonic Adventure 2 because Shadow impersonated Sonic and had him thrown in jail at Prison Island. Towards the end of the game, they became allies when they had to save the planet from the Space Colony ARK.
The first real fight between them happened in Sonic Heroes when Team Dark provoked Team Sonic into battling them, although Shadow did not remember Knuckles or Sonic or Tails. After the fight, Knuckles jokingly mentioned that they might have fought Shadow's ghost.
In Shadow the Hedgehog Knuckles appears in Glyphic Canyon, Central City, and Black Comet stages asking for Shadow's help in Hero missions.
In Sonic the Hedgehog (2006) he and Shadow were loosely allies in the game, and they worked together again for a time in order to return to the present.
Shadow and Knuckles appear to have some bitter resentment towards each other as seen in Sonic Rivals when Shadow bluntly pointed out that Knuckles was useless for his shortcomings while retaining an indifferent attitude towards his challenges, and Knuckles seemed to be irritated by Shadow's presence. Knuckles seems to find Shadow and his indecisive attitude and smug demeanor annoying, and it is likely that Shadow's inflated ego tends to rub Knuckles the wrong way, and an example of this is seen in Sonic Free Riders when Knuckles pointed out that Shadow had a big ego in a rather annoyed tone. In Sonic Forces, Knuckles was shocked to hear about Shadow causing trouble in Sunset Heights, wondering why he would "work for the enemy". As it turned out that the real Shadow was not working with Eggman, Knuckles fought alongside him in the penultimate battle against the Eggman Empire as an ally. Overall, Knuckles and Shadow's relationship revolves around their goals.
In Mario & Sonic at the Olympic Games Tokyo 2020, Knuckles and Shadow teamed up to compete with Princess Peach and Yoshi at the Badminton court. They seemed to have ignored each other after they lost, with Knuckles being ashamed at his loss while Shadow claiming he would have won if it was just him.
Vector the Crocodile
Knuckles and Vector are on good terms with each other, having been friends since the Chaos Ring incident. However, they do not interact often with one another in the present day. Regardless, Vector gave advice to Knuckles when Team Sonic was fighting Metal Overlord, apparently acknowledging his great power.
In Sonic Free Riders, the two did not have a friendly relationship, as Knuckles felt underwhelmed having to race against Vector and the rest of Team Rose, treating them like a joke as he was irritated by their loud behavior. Although Vector managed to defeat Knuckles one time, the echidna still said he would not get far with brute force, enraging the crocodile.
In Sonic Forces, the two were comrades in the game, and they appeared to work very well together, as Vector was a high-ranking member of the Resistance. The two also appeared to have considerable respect for each other, and Vector unsurprisingly appreciated Knuckles for his aggressive (yet sometimes short-sighted) generalship considering Vector's own liking of non-peaceful methods.
In the Nintendo 3DS version of Mario & Sonic at the London 2012 Olympic Games, they trained together prior to the Olympics and later teamed up to track down Bowser. They also have a special winning animation in Mario & Sonic at the Sochi 2014 Olympic Winter Games and Mario & Sonic at the Rio 2016 Olympic Games.
Rouge the Bat
Rouge the Bat is Knuckles' primary rival. Knuckles and Rouge have been fighting over the Master Emerald since the two first 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, they became enemies when they met because Rouge had stolen the Master Emerald from him, and she was working with Shadow and Eggman. Also, 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 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 of the identity of her client. They fight the Ifrit to get back to normal depending on which side you play. Knuckles also asked Rouge if she was alright when they won against the Ifrit, showing his concern for her, and the only reason why he fights her in the last level is because she's struggling to break free from mind control.
In Sonic the Hedgehog (2006), Rouge and Knuckles were bitter allies during their mission to travel back to the present day but joined up with him to collect the seven 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. They are also friendly with each other in Sonic Forces, and Rouge holds no qualms with being a spy under Knuckles' command, even acknowledging him as "boss".
Blaze the Cat
Knuckles first met Blaze when Cream wanted Blaze to be friends with him. Knuckles was initially very friendly and cordial towards Blaze before he noticed Blaze holding a few Sol Emeralds, which he mistook for Chaos Emeralds. He therefore gave Blaze advice to give them to Sonic. Blaze got angry at Knuckles and told him that she did not have any Chaos Emeralds. Knuckles then got angry at her and accused her of lying, and then made an attempt to attack her. Blaze dodged Knuckles' attack and knocked him out, leaving him to lie in a crevice. When Knuckles regained consciousness, he developed a loathing towards Blaze and wanted revenge. When they met once again, Knuckles nearly started a fight with Blaze, but he was stopped by Amy. Cream also convinced Blaze that Knuckles was actually a "nice guy", which made Blaze feel relieved. Soon, Knuckles let go of his grudge and befriended Blaze.
Storm the Albatross
When Knuckles and Storm the Albatross met, Knuckles punched Storm really hard while the latter was trying to commit a theft, which caused Storm to fall from his Extreme Gear. Ever since then, the two have been rivals over who is the stronger man. When Storm lost against Knuckles in the World Grand Prix, he falsely accused him of having cheated. In Sonic Riders: Zero Gravity, the two also showed a spark of anger when they saw each other again. In this encounter, Knuckles thought of Storm as a "meathead" while Storm wanted to settle the score between them, causing great tension between the two.
Silver the Hedgehog
Knuckles and Silver the Hedgehog appear to have a friendly relationship with a small rivalry between the two. Although they do not have much interaction with each other, they have had heated battles with one another occasionally. Knuckles initially showed his dislike of Silver when he first met him, mainly because he thought that he was pompous and stuck-up. Silver's haughty and prickly attitude also tended to annoy Knuckles. However, they later put aside their differences, and willingly teamed up together. In Sonic Forces, Knuckles was the first person Silver warned about Eggman's attack, which led to the War to Take Back the Planet. In the game, Knuckles and Silver appear to be on very good terms with each other, and work very well together. In fact, Silver appeared to be one of Knuckles' most trusted lieutenants, indication that Knuckles has considerable respect for Silver.
- Sonic the Hedgehog (best friend, teammate, and rival)
- Miles "Tails" Prower (best friend and teammate)
- Amy Rose
- Cream the Rabbit
- Big the Cat
- Team Chaotix
- Shadow the Hedgehog (rival)
- Rouge the Bat (friendly rival)
- E-123 Omega
- Lumina Flowlight
- Blaze the Cat
- Silver the Hedgehog (rival)
- Vanilla the Rabbit
- Shade the Echidna
- Classic Sonic
- Classic Tails
- Dodon Pa
- Sonic the Hedgehog (friendly rival)
- Rouge the Bat
- Emerl (friendly rival)
- Shadow the Hedgehog
- Silver the Hedgehog
- Storm the Albatross (arch-rival)
- Eggman Empire
- Eggman Nega
- Fang the Sniper
- Black Arms
- Babylon Guardian
- Classic Eggman
- The Time Eater
- Calculation: Knuckles' strength predicated on Sonic's running:
A 100-ton object requires a force that is at least equal to 1,000,000 newtons
- Force x distance = Work = Energy
- (Sonic's mass in kilograms) x 340^2 (Mach 1), which would be equal 2,026,452 joules
- Sonic Channel (Japanese). Characters: Knuckles. Sega. Archived from the original on 26 May 2019. Retrieved on 3 July 2015.
- Sonic Team (31 July 1997). Sonic Jam. Sega Saturn. Sega. Area/Level: Sonic World, Museum. "Knuckles the Echidna profile."
- Sega of America . Knuckles the Echidna. Sonic Characters. Sega. Archived from the original on 5 March 2005. Retrieved on 26 October 2017. "Knuckles was born alone on Angel Island, brought into this world to defend the Master Emerald. That is Knuckles' destiny and fate. If Sonic exemplifies the wind, then Knuckles is the mountain: stern and unmovable. Knuckles is quick to anger, but cool and determined in battle. Even though he considers Sonic his friend, the disposition of the Master Emerald is his ultimate concern. His determination to protect the gem from harm or ill use is set in stone and is unshakable. He is often envious of the adventurous lifestyle Sonic lives and the fame that has followed from Sonic's deeds, but Knuckles is well known in his own right, as a treasure hunter versed in the martial arts."
- Sonic the Hedgehog 3 (Sega Mega Drive) Japanese instruction booklet, pgs. 34-36.
- Sonic the Hedgehog 3 (Sega Genesis) United States instruction booklet, pg. 6.
- Devra Newberger Speregen (2016). Sonic: The Ultimate Character Guide. Scholastic. p. 15. ISBN 978-1338033243.
- Sonic & Knuckles (Sega Genesis) United States instruction booklet, pg. 7.
- Knuckles, at the end of his story in Sonic Adventure.
- Sonic City. Archived from the original on 25 February 2008. Retrieved on 3 April 2008.
- Sumo Digital (23 February 2010). Sonic & Sega All-Stars Racing. PlayStation 3. Sega. "Knuckles the Echidna's profile card: Knuckles the guardian of the Master Emerald, which gives Angel Island its power to float in the sky. He is the last of the Echidnas - the island's native people. His name comes from his powerful fists, which allow him to punch through rock and make him a skilled burrower and climber. He can also use his dreadlocks to glide for short distances."
- Sonic the Hedgehog 3 (Sega Mega Drive) Japanese instruction booklet, pgs. 34-36.
- Sonic's Creator - Yuji Naka. Sega. Archived from the original on 5 June 1997. Retrieved on 28 August 2008.
- "ソニックザヘッジホッグ３ / 誰もが驚いたロックオンシステム". Sega Magazine (Soft Bank) (8): 14–15. 13 June 1997. Archived from the original.
- Interview with Roger Hector, former Director of Sega Technical Institute. Secrets of Sonic Team. Retrieved on 28 February 2008.
- "Sonic the Hedgehog Staff Interview - We Ask Yuji Naka about the Possibility of a Saturn Sonic". Sega Saturn Magazine (Soft Bank): 84–85. 7 January 1995. Archived from the original.
- "新キャラクター"ナックルス"". Sega Magazine (Soft Bank) (8): 14. 13 June 1997. "「3」は最新作だから、当然新キャラも、ということから、新規にデザインされたナックルズ。 当時はちょうど「ジュラシックパーク」を受けての恐竜ブームだったことから、最初は恐竜っぽいデザインから始まったというが、その後デザイン担当の湯田氏によってリファインされ、 アメリカ人好みのドレッドヘアになっていくことになる。"
- "誰もが驚いたロックオンシステム". Sega Magazine (Soft Bank) (8): 15. 13 June 1997. "当時新人だった飯塚氏は、この時の開発で大いに成長を遂げた一員だ。 ちなみに 「 3 」の新キャラナックルズは、じつはスタッフの間では赤や緑などの候補があがっていて中氏は紫を押していたとか。 でも、実際にアメリカの子供達を対象にリサーチをしたら、圧倒的に赤が大人気だったそうだ。"
- Sonic Central interview: Yuji Naka on Sonic's Past, Present, Future. Sega. Retrieved on 7 July 2008.
- Mylonas, Eric (11 March 2003). Sonic Advance 2: Prima's Official Strategy Guide. Prima Games. p. 99. ISBN 0761540083.
- Theobald, Phil (27 January 2006). Sega Talks Sonic Riders Part Two. GameSpy. Retrieved on 2 April 2014.
- Knuckles the Echidna Biography. IGN. Archived from the original on 4 March 2014. Retrieved on 26 October 2014.
- Thomas, Lucas M. (12 October 2007). Smash It Up! - Sonic Team. IGN. Retrieved on 26 October 2014.
- Sega . Official Sonic Heroes website (Japanese). Characters: Team Sonic. Sega. Archived from the original on 7 December 2004. Retrieved on 25 May 2021.
- Sonic Heroes (PlayStation 2) United States instruction booklet, pg. 5.
- Sonic Jam (Sega Saturn) Knuckles the Echidna profile.
- Sonic Team, Sonic Team USA (27 February 2004). Sonic Battle. Game Boy Advance. Sega. Area/Level: Holy Summit (Sonic's Episode). "Sonic: Don't worry. He's got lots of power, but his moves are simple to read. Watch for an opening, then hit him with a combo attack!"
- Sonic Team (27 January 2004). Sonic Heroes. Xbox. Sega. Level/Area: Opening.
- Sonic Rivals 2 (PlayStation Portable) United States instruction booklet, pg. 7.
- Sonic Heroes (PlayStation 2) United States instruction booklet, pg. 18.
- Sonic Team, Sonic Team USA (27 February 2004). Sonic Battle. Game Boy Advance. Sega. "Deep Impact: Knuckles's[sic] ground power. His Vigorous Straight Punch causes explosions with its enormous power."
- Sonic Team (3 May 2002). Sonic Adventure 2: Battle. Nintendo GameCube. Sega. Cutscene: Enter Knuckles.
- Sonic the Hedgehog Technical Files
- Sonic Team (27 January 2004). Sonic Heroes. Xbox. Sega. Level/Area: Ending sequence (Last story).
- Sonic Team (21 February 2006). Sonic Riders. Nintendo GameCube. Sega. Level/Area: Opening sequence.
- Sonic The Hedgehog 4. Sega. Archived from the original on 12 May 2013. Retrieved on 27 October 2017.
- Sonic Team, Sega Technical Institute (18 October 1994). Sonic & Knuckles. Sega Mega Drive. Sega. Area/Level: Opening sequence (Knuckles' story).
- Sonic Team, Dimps (28 March 2003). Sonic Advance 2. Game Boy Advance. Sega. Area/Level: Ending sequence (Knuckles' story).
- Sonic Team (11 November 2011). Sonic Generations. PC. Sega. Area/Level: Knuckles: Horde of Enemies.
- Sonic Team (27 June 2003). Sonic Adventure DX: Director's Cut. Nintendo GameCube. Sega. Area/Level: Egg Carrier. "Knuckles: I can sense the Emeralds are here somewhere!"
- Sonic Team (27 June 2003). Sonic Adventure DX: Director's Cut. Nintendo GameCube. Sega. Area/Level: Egg Carrier. "Knuckles: I sense the Master Emerald. It can't be far from here."
- Sonic Team (3 May 2002). Sonic Adventure 2: Battle. Nintendo GameCube. Sega. Cutscene: Last Chance. "Knuckles: I feel some strange energy..."
- Sonic Team, Dimps (15 November 2005). Sonic Rush. Nintendo DS. Sega. Area/Level: Zone Map (Blaze). "Knuckles: Hmph! Why do you look so suspicious? What do you have in your hands? / Blaze: Hmm...! / Knuckles: I sense a familiar power... Do you have Chaos Emeralds? / Blaze: (Chaos Emeralds?) (Are there gems here akin to the Sol Emeralds?)"
- Sonic Team, Sonic Team USA (27 February 2004). Sonic Battle. Game Boy Advance. Sega. "Knuckles Heal: Knuckles' heal skill. Uses earth elementals to heal damage."
- Sonic Team, Sonic Team USA (27 February 2004). Sonic Battle. Game Boy Advance. Sega. "Meteor Crush: Knuckles' air shot. He makes rocks fall from the sky using the supernatural power of the earth."
- SONIC RUNNERS [SEGA]. Sega. Archived from the original on 26 February 2025.
- Sonic Team (25 February 2015). Sonic Runners. iOS. Sega. Area/Level: Episode 25-1. "Knuckles: Heh! You know my treasure-hunting instincts never fail!"
- Sonic Team (25 February 2015). Sonic Runners. iOS. Sega. Area/Level: Episode 37-1. "Knuckles: Hold up, my treasure sense is tingling... Here! Right...here!"
- Sonic Team (3 May 2002). Sonic Adventure 2: Battle. Nintendo GameCube. Sega. "Sonic: We're counting on you buddy! The world's greatest treasure hunter!"
- Sonic Team (25 February 2015). Sonic Runners. iOS. Sega. Area/Level: Episode 25-1. "Knuckles: Yeah... I got a sniff of treasure a little while back, and it's getting stronger... Let's see now... Aaand... Bingo!"
- Sonic Free Riders (Xbox 360) United States instruction booklet, pg. 10.
- Sonic Team, Dimps (3 February 2002). Sonic Advance 2. Game Boy Advance. THQ. Area/Level: Sky Canyon Boss Attack.
- Sonic Team (3 May 2002). Sonic Adventure 2: Battle. Nintendo GameCube. Sega. Cutscene: Cutscene 1 (Last Story). "Sonic: Heh, just letting Knuckles pilot the shuttle all the way over here, was more dangerous than you could ever be!"
- Sonic Advance 3 (Game Boy Advance) United States instruction booklet, pg. 12.
- Sega (23 June 2016). Mario & Sonic at the Rio 2016 Olympic Games. Wii U. Nintendo. Area/Level: Collectibles (Flags). "A red echidna that boasts some serious muscle, Knuckles is what one might call "best frenemies" with Sonic."
- Sega . ソニック ＆ ナックルズ (Japanese). Sonic Channel. Archived from the original on 20 January 2021. Retrieved on 27 January 2021.
- Sonic Team, Dimps (9 March 2003). Sonic Advance 2. Game Boy Advance. Sega.
- Sonic Advance 3 website (Japanese). Retrieved on 1 May 2015.
- Sega . Sonic the Hedgehog European site. Characters: Knuckles the Echidna. Archived from the original on 15 March 2007. Retrieved on 5 May 2015. "Sonic's famous sidekick spends most of his time alone on Angel Island guarding the Master Emerald, so he's always happy to help Sonic out especially if it involves scrambling Dr. Eggman's evil plans for world domination."
- Sonic Team (6 February 2004). Sonic Heroes. PlayStation 2. Sega. Level/Area: Metal Overlord. "Vector: We have to counter the battleships he throws with power! Knuckles... Show him your powerful punches, OK? Don't hold back anything!"
- Sonic Team (7 November 2017). Sonic Forces. PlayStation 4. Sega. Level/Area: Capital City. "Vector: Ha! Great speech! Let's give Eggman an old-fashioned beat down!"