Knuckles the Echidna/Miscellaneous

Sonic Underground
In Sonic Underground, Knuckles is the lone guardian of the Chaos Emerald on the Floating Island and is mentored by his great-grandfather Athair. While he was a kid, he met Queen Aleena who told him that he would be the first ally of her children Sonic, Manic and Sonia to join them in the war against Dr. Robotnik.

Years later, Knuckles met Sleet and Dingo who tricked him into believing that Sonic, Manic and Sonia were thieves after his island's Chaos Emerald. When Sonic, Manic and Sonia arrived on the Floating Island to find their mother, Knuckles attacked them until Sonic saved his life. After clearing up the misunderstanding, Knuckles and the hedgehog siblings teamed up to reclaim the Chaos Emerald Sleet and Dingo had stolen before the island fell from the sky and they became the allies Aleena wanted. When Dr. Robotnik found another Chaos Emerald, Knuckles aided Sonic, Manic and Sonia in reclaiming and containing the Chaos Emerald when it ran rampant.

Sonic X
In the anime series Sonic X, Knuckles originally lived on a parallel version of Earth in another dimension, where he guards the Master Emerald. He takes his job seriously and has a fearsome temper with a "chip on his shoulder". During one of the battles with Dr. Eggman, an accidental large-scale Chaos Control sent Knuckles, Sonic, Dr. Eggman, and their friends to the human world. Upon becoming stranded in this world, Knuckles' only desire was to get back to Angel Island quickly. Preferring to do things his own way, Knuckles spend most of his initial time on Earth traveling alone rather than joining up with Sonic and their friends, though he would occasionally come to their aid to fight Eggman and befriend others.

When Angel Island was transported to Earth after he failed to work together with Eggman to bring them back home, Knuckles returned to guarding the Master Emerald while helping Sonic with other major threats. Eventually though, Knuckles and everyone from his world returned home after learning their presence was threating to freeze time.

Six months after returning home, Knuckles was persuaded to join Sonic and his friends in their fight against Metarex, an alien race of cyborgs that was a threat to the safety of the entire galaxy, when they needed him and the Master Emerald to power the Blue Typhoon. During the final showdown, Knuckles was forced to sacrifice the Master Emerald to defeat the Metarex's leader, Dark Oak. After defeating the Metarex, Knuckles returned home to look over the Master Emerald until its power could return naturally.

Sonic the Hedgehog: The Movie
In Sonic the Hedgehog: The Movie, Knuckles is a traveling treasure hunter who roams the Land of Darkness, and a long-time friend of Sonic the Hedgehog and Tails.

When Sonic and Tails came to the Land of Darkness to stop the Robot Generator, Knuckles came to the duo aid when they came under attack by Metal Robotnik and helped destroy the metallic menace. When it turned out that the Robot Generator was a trap made by Dr. Robotnik to complete Hyper Metal Sonic, Knuckles helped Sonic, Tails and their allies keep Metal and Robotnik from destroying the world.

Sonic Boom
In the Sonic Boom franchise, Knuckles hails from Angel Island and is the muscle of Team Sonic, a group of heroes who protects Seaside Island and the earth at large from Dr. Eggman and his legion of robots. An orphan and the last of his kind, Knuckles is not very bright, less independent and a little slow on the uptake, but he still has his soft spots: he loves nature and is extremely loyal to his friends. Also, while they are friends, Knuckles has a friendly rivalry going on with Sonic.

Archie Comics
In the Sonic the Hedgehog comic book series and its spin-offs published by Archie Comics, Knuckles was the eighteenth Guardian of Angel Island and a member of the Brotherhood of Guardians. Born to Locke and Lara-Le, Knuckles' DNA was indirectly tampered with and his unhatched egg was irradiated with Chaos Emerald radiation by Locke so he had a chance of facing a horrible threat in the future which Locke had seen in a vision. The result was a child with incredible powers–a "living Chaos Emerald."

Knuckles was raised by in Guardian tradition by his father in the wilds on Angel Island and then left to fend for himself at ten. Knuckles learned self-reliance while his forefathers monitored his process, sometimes lending him a hidden hand. Despite the Brotherhood's neutrality, Knuckles joined the First Robotnik War after a meeting with Sonic the Hedgehog and later the Second Robotnik War. The mysteries around his life began to unravel when the effects of the Ultimate Annihilator returned both the Dark Legion and the city of Echidnaopolis to Angel Island. Knuckles was exposed to a family and heritage he knew he had.

As his prowess grew in facing new challenges, Knuckles' Chaos power grew out of control, transforming him into Chaos Knuckles, a form with god-like power, but had little to no control. The transformation culminated when Knuckles was forced to fight Mammoth Mogul to save his distant ancestor and old foe Dimitri, where he released all his power to stop Mogul and died in the process. Knuckles joined the Chaos Force to a degree even the Ancient Walkers had reached. However, with his cosmic awareness, he sensed the Xorda Invasion of Mobius. Using his unlimited power, Knuckles returned to life - but sacrificed his "living Chaos Emerald" quality, leaving him weak and powerless until the Master Emerald's energies restored his powers. His Chaos Force connection was later abused Dr. Finitevus who used dark magic to transform Knuckles into Enerjak. As Enerjak, Knuckles made sweeping changes to Angel Island and the world. He was restored, but at the cost of Locke's life, making him withdrawn to almost everyone. He endured further losses when he later lost almost all the echidnas on Mobius to Thrash the Tasmanian Devil.

Following the events of Worlds Collide, Knuckles and his history became nearly indistinguishable from his game counterpart. Assisting in the Shattered World Crisis, Knuckles went on a hunt for the Master Emerald's shards after shattering it to keep it safe.

Sonic the Comic
In Sonic the Comic, 8,000 years ago, Knuckles was the leader of the Echidna Empire's armies under Pochacamac, fighting the Drakon Empire. Presumably by being placed in suspended animation, Knuckles survived to the present day, but with no memories of his earlier life. Seemingly the only echidna left in this era, Knuckles came to live on the Floating Island where he alone guarded the Chaos Emeralds. In addition to a near obsession of protecting his island, Knuckles is greatly affected by the uncertainty of the fate of his own people.

When Dr. Robotnik and his Death Egg II crashed on the Floating Island, Knuckles was tricked by the doctor into believing Sonic the Hedgehog sought to steal the island's Chaos Emeralds. Knuckles thus allowed Robotnik to rebuild the Death Egg II on the island and assisted him in fighting Sonic and stealing Sonic's own six Chaos Emeralds so they could be combined with Knuckles' into one set of Emeralds. Knuckles, however, was skeptical enough to conceal that he had the missing Grey Emerald, so when Robotnik revealed his betrayal and tried to absorb the Emeralds' power, Knuckles used the Grey Emerald to defeat him.

From that point on, Knuckles worked as an ally to the Freedom Fighters in the battles with Robotnik. When Dr. Zachary appeared, Knuckles stopped him from destroying Mobius, but then had to spend the next period undoing the subsequent damage to the Floating Island, which culminated as he returned home to stop Robotnik and Zachary from turning the Emerald Hill refugees into an organic computer. After Robotnik had been overthrown, Knuckles came to help Sonic and his friends' with the following threats, such as when Robotnik tried to force Mobius into environmental collapse and when Chaos was unleashed.

Reception
The character has received generally positive attention. According to IGN, fans "seemed legitimately happy" with the addition of the character of Knuckles, who was popular enough to get marquee billing in Sonic & Knuckles, but the writer felt that characters that came after him were going "overboard." IGN's Colin Moriarty singled out the introduction of both Knuckles and Tails as when the series became "iffy" and listed them and all other characters in the series, sans Sonic and Robotnik, as being 2nd most in need to "die" on his top 10 list. In contrast, he was listed as the best Sonic character by Official Nintendo Magazine based on the impact he brought to the Sonic games in which he first appeared.

Complex listed Knuckles as their eleventh most wanted character in the next Super Smash Bros. game. In another article, Complex regarded Knuckles as a better character than Sonic, and praised his gliding and climbing abilities, stating "even if his levels were a little more challenging than Sonic's, the thrill of being able to explore certain parts of levels that the blue-colored hero could not was worth it". Game Rant included Knuckles on their list of "Top 10 Third-Party Characters that Could Appear in the New Super Smash Bros.", commenting "This punch-drunk brawler knows how to serve up a buffet of knuckle sandwiches, and there’s no question that he’s one of the most fitting characters to occupy a spot on the roster".

Mega Zone's review of Knuckles' Chaotix praised the introduction of a new protagonist, whom it deemed "rougher [and] tougher" in comparison to the "spineless" Sonic. Mean Machines Sega called Knuckles' powers "impressive" and the character overall more useful and promising than Tails.[80] Sega Magazine stated that Knuckles "looks cooler" than Sonic, comparing him to Spider-Man, and suggested he be given his own game. Sega Magazine later called him "groovy" and "ace", concluding that they "love him."

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

Quotes

 * "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.
 * "No way!" - When Knuckles tries to dig on something like metal or steel in Sonic Adventure.
 * "It's closer..." - When the Emerald Radar turns red.
 * "I sure don't wanna fall off." - Knuckles when the player turns the camera too much in Sonic Adventure.
 * "My emerald, my destiny" - Getting a piece of the emerald on 2-Player mode of Sonic Adventure.
 * "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.
 * "Ah finally..." - Restoring the Master Emerald in Sonic Adventure 2.
 * "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.
 * "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.
 * "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.
 * "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
 * "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 must...protect...the Master Emerald..." - Knuckles, after losing to Rouge in their first, and only, battle on the ARK, in Sonic Adventure 2.
 * "I'm just warming up!" - Sonic Heroes.
 * "Time for a Knuckles sandwich!" - Knuckles taunting the opposing team in the minigames of the 2P Battle mode of Sonic Heroes.
 * "Whew, that was pretty tough." - Knuckles when defeating Metal Overlord in Sonic Heroes.
 * "Just enough to pass." - Getting an E Rank in Sonic Heroes.
 * "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.
 * "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.
 * "Stone Fists! - After winning a fight in Sonic Battle.
 * "It's not me! Blame Sonic!" - When talking to Rouge in the Japanese version of Sonic Battle
 * "Me? My fists are my weapons of choice." - Knuckles saying that he would rather use his fists than a gun in Shadow the Hedgehog.
 * "What do you think you're doing Shadow!?" - Knuckles when Shadow destroys a G.U.N. robot or soldier in Shadow the Hedgehog.
 * "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.
 * "Stop attacking the good guys!" Knuckles when Shadow destroys a G.U.N robot or soldier in Shadow the Hedgehog.
 * "Help! We're being sucked in!" - Knuckles when he gets sucked into the tornado in Shadow the Hedgehog.
 * "Outta my way!" - When attacking in Sonic Riders and 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.
 * "Did she say, "Red mutt"...?" - After Wave calls him a red mutt before leaving with Storm on the Babylon Garden in Sonic Riders.
 * "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).
 * "Still got it!" - Winning in Sonic Rivals 2.
 * "Hand it over Eggman. I'm losing my patience." - Knuckles demanding Eggman to give him the Emerald Detector in Sonic Rivals 2.
 * "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.
 * "Let's go... Yah!!" - About to perform a Gravity Dive in Sonic Riders: Zero Gravity.
 * "A trap!? What have you done Eggman!?" - Knuckles confronting Dr. Eggman at the top of Crimson Tower 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.
 * "How long are they going to make us wait? All this pent up energy is making me itch." - Knuckles in Sonic Free Riders.
 * "I'll handle the treasure hunting!" - Knuckles before the Sky Sanctuary mission with Modern Sonic begins.
 * "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.
 * "Come on Sonic, smack him!" - Knuckles cheering the Sonics to keep going in Sonic Generations.
 * "We're fighting to get our world back now. Don't stop, don't look back! Just focus on the task ahead no matter what! Let's do this, everyone!! CHARGE!!!" - Knuckles instructing the Resistance in Sonic Forces.

Solo

 * Knuckles has his own percussion theme in Sonic 3 & Knuckles.
 * In addition, the game has two different themes depending on the version. In the standalone version of Sonic the Hedgehog 3, the song had techno beats. In Sonic & Knuckles as well as the combined version, it's changed to the aforementioned percussion theme.
 * 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."

Trivia

 * According to the Sonic the Hedgehog 3 manual, Knuckles' favorite food is grapes. This is referenced many times through the series.
 * In Sonic Generations, once Sky Sanctuary and Knuckles are restored, grapes can be seen growing on a tree behind Knuckles. This is an Easter Egg for Knuckles, as grapes are his favorite food.
 * Strangely, in Sonic the Hedgehog 3, Sonic & Knuckles, and Sonic the Hedgehog 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.
 * Due to Knuckles' guillible nature, he has a tendency of getting tricked by his nemesis, Dr. Eggman, (and/or his lackeys) either to work for him or, against his allies/friends, particularly Sonic and Tails. This mostly occured during the classic games, and has mostly faded out as time passed.
 * Knuckles' counterparts in spin-off media also suffer from this problem. As an example, he has been tricked four times in Sonic X.
 * In Sonic the Hedgehog 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.
 * In the earlier games, 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 five letters.
 * Due to space limitations, in Sonic Drift 2, Knuckles' name is spelled "Knucles", without the second "K".
 * Knuckles' 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, though neither were seen nor mentioned in the released game.
 * 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 the Hedgehog (2006) who does not finish a level/boss/town mission. Despite this, Knuckles does have a victory pose and quotes depend on the rank.
 * 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 and shoes have been miscolored multiple times:
 * In Sonic the Hedgehog 3, Sonic the Hedgehog Triple Trouble and Sonic & Knuckles, Knuckles' socks were colored yellow during cutscenes, as it interfered with the HUD palette. The playable version of Knuckles has green socks, though.
 * In Sonic Drift 2 and Sonic 3D Blast, Knuckles' socks were colored blue.
 * In Sonic R, Knuckles' shoes instead resemble Tails' white-tipped shoes, save for the metal tops and green socks. In still art, however, his shoes are correctly colored, but the yellow stripe covers the back too.
 * In 2D games such as Knuckles Chaotix and Sonic Mania, Knuckles is colored pinkish rather than red. However, his official artwork shows him colored correctly (red).
 * The crest on Knuckles' chest has been erroneously colored peach several times. In later games, though, 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 the Hedgehog 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 a play on the Japanese term for echidna, which literally translates as "needle-mole".
 * If the player pauses at the right moment, in Sonic the Hedgehog 3, when the sign is twirling in the air, Knuckles' color will be blue instead of red. This does not occur in Sonic & Knuckles.
 * Super Sonic is invincible to any damage, but somehow Knuckles knocked the Chaos Emeralds out of him in Sonic 3 & Knuckles.
 * In Sonic the Hedgehog 3 & 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.
 * Knuckles' gloves are a "Rare" weapon in the SEGA game Phantasy Star Portable 2; it was named "Sonic Knuckles", either referring to the strength or to the universe of the Sonic series.
 * There is a possibility that this ability of Knuckles' treasure hunting ability is a reference to the fact that real-life echidnas are equipped with electrosensors.