Kuroobi, part of Arlong's Quirky Miniboss Squad. He brags about his prowess in Fishman Karate, gets Sanji on the ropes for most of their fight due to most of it taking place in water, and only loses because he stops to boast and can't finish his ultimate move (when he first attack hardly did any damage at all) resulting in Sanji curb-stomping him. As a bonus, his name translates to English as "black belt".
Bellemy constantly thinks he's more powerful then Luffy due to the belief that Luffy is weak because he still believes in his dreams and had let Bellemy beat him up as he found fighting him pointless. Plus he regarded bounties as power levels and that his 55,000,000 Beri trumped Luffy's (at the time) 30,000,000 Beri. However, Bellemy made the mistake of beating up his friends and disregarding the new 100,000,000 Beri bounty as an attempt to scare him. So when the two confronted each other again, it was virtually a no contest; Luffy floored himwith one hit.
At first, Whitebeard appeared to be like this, ripping up Shanks' letter and demanding he come in person to deliver his message. However, we see that Whitebeard may be proud but not smug. He is fully aware of his decreasing health and when one of his comrades stabbed him, rather than kill the guy outright, he calmly embraced the traitor, calling him his son and forgiving him. He had charged into battle, expecting to die, in order to save Ace. If anything, he is more of a Jerk with a Heart of Gold.
Rob Lucci. Gives up his key so it won't distract from his fight with Luffy. Is unconcerned about anything else but defeating Luffy. Trash talks through the entire thing about how he is more powerful than a mere pirate. And unlike virtually every One Piece main villain, he never suffers a Villainous Breakdown. He's arrogant up until the exact moment of his defeat, and doesn't have time for anything but an Oh Crap.
The signature Uchiha arrogance reaches a peak in ol' Madara himself, who has powers close to a god and will not hesitate to remind you of it.
Any and all villains from 'Dragon Ball'', particularly Frieza, Tao Pai Pai, Vegeta, and Tien (though the latter two did a Heel-Face Turn).
Hercule/Mr. Satan is a subversion. He's the official world martial arts champion (a title he got because Goku and his friends were too busy saving the world to participate in the tournament) and incredibly arrogant about it. He thinks Dudes flying around and shooting energy blasts are all trickery, and when he learns that it's real, he still acts like it isn't publicly. Among all the main characters in the series, he's easily the weakest. At the same time, he is legitimately the greatest martial artist in the world among normal human beings, so it's not like that bravado comes from nowhere either.
Ruki Makino/Rika Nonaka (depending on the dub) from Digimon Tamers. Being a Mon series, this applies to her tactical abilities rather than her melee prowess, to the point where she nearly has the main character's partner killed for experience. This attitude only lasts until she acknowledges that Digimon are living beings.
Samurai Champloo featured Shouryuu, a Japanese kendo student-cum-Shaolin martial arts master who killed reputable samurai in order to prove his superiority. He takes every fight seriously; After his return to Japan, he killed another student during a sparring match.
In B't X, there's Ron, the hot-headed spiritual guardian.
Tatewaki Kuno also fits, for the most part, except for the fact that most other characters could kick his ass in their sleep once he falls victim to Can't Catch Up. Apparently, he's too arrogant to realize he needs to improve.
It helps that he's too stupid to die. People improve in response to threats, and nothing can actually threaten him - and since he Can't Catch Up, he's not enough of a threat to anyone else to really get things going.
Mousse doesn't qualify quite as much as Ryouga, but almost. Fortunately, like Ryouga, he has an easily-exploitable weakness in his absolutely terrible vision. He's hiding an infinite supply of glasses in his robes, but it still takes time to put on a new pair.
Ryu Kumon is probably one of the only characters in the entire manga who isn't at all humorous ever at all ever (especially in his backstory). A completely ruthless fighter who causes only senseless destruction.
Pantyhose Taro. He's a martial artist capable of resisting Ranma in a normal fight even before using his Jusenkyo curse to become a giant flying minotaur (later with Combat Tentacles tentacles and ink) able to fight off most of the Nerima Wrecking Crew at once. He's also ruthless, clever and underhanded.
Herb of the Musk.
Ranma himself is like this sometimes.
Shampoo fits this well, even to Ranma (hint: she's in Japan for losing against Ranma and the gap just keeps getting bigger).
Akane fits this on the count that she gets jealous easily of anyone whose fighting ability exceeds her own (which is everyone after Ranma came into the picture). She's also a sore loser who'd do anything to win a fight (like Super Soba and Battle Dogi).
Satsuki Arashiyama of Nanaka 6/17, whose constant aggravation is due to no one taking her seriously and Nanaka accidentally foiling her at every turn. Despite this, she's an incredibly competent swordswoman and downright deadly roughly 100% of the time.
Hyoutei's Hiyoshi from The Prince of Tennis, whose Enbu tennis style is based on Kobujutsu (an ancient martial arts from Okinawa). Not really a people person, often seems to be annoyed or angry, and his philosophy in life is gekokujo (which means that subordinates will surpass, defeat and take the place of their superiors... similar to putting fools in their place, in a way).
Rikkai's Sanada is such an arrogant kung fu guy that his signature move Fuurinkazan comes straight out of The Art of War.
This is a definite description for Kurogane, of Tsubasa.
However, he slowly warms up his traveling companions (especially Fai), and begins to value their well-being and safety above everything else. He even decides that fighting is only justified if it's to protect someone important.
Ginga Izumo, one of the heroes of GEAR Fighter Dendoh, is a lesser (hey, he's only 10) version of this trope at the start of the series. Being forced to work with the much more mellow Hokuto keeps him from ever venturing into the full blossom of this trope.
Except Boris. Out of like fifty villains (... recurring, post Heel-Face Turn or no...) there had to be one eventually who admitted Kenichi didn't suck before actually losing, right?
Out of Yomi, Boris, Ethan, and Chikage all act more like a Punch Clock Villain than anything else. The rest of Yomi, and almost all the Fists of Ragnarok, fit this trope well.
Card Captor Sakura — Syaoran, though this is cheerful shoujo fare so it's toned down. But as far as he's concerned, no one but him is entitled to the Clow Cards and Sakura's name is 'weakling'. At first...
Several of the villains in Bleach act like this, but many of them change after their initial appearance. Yammy takes the cake though.
Nnoitra. He's capable of going over anyone and everyone just to show that he's better than everyone - this shows in his shared backstory with Neliel, whose repeated ass-handing to him made him inflict severe head trauma on her to turn her into a kid and, thus, kick her out of Las Noches. And, for bonus points, his reasoning is combined with pure machismo here: not only he didn't accept to be bested in battle, but it always stuck in his craw to be regularly beaten by a woman.
Kyuzo of Samurai 7 is a cross between this and Aloof Ally. He is very, very good, and enjoys fighting (which seems to be all he knows), but he's too much the strong silent type to brag about it.
Kongo Agon of the Shinryuuji Nagas from Eyeshield 21 is Neji in football gear. Made worse in the fact that his team and seemingly everyone around him goes out of their way to enable him... Except the Devilbats.
Paul of Pokémon, to the extent that even one fair and square crushing loss haven't changed his attitude.
All top-tier martial artists from Fist of the North Star, except Toki. Unless really being that good, or less than completely antisocial, disqualifies you, in which case the chief protagonist, Kenshiro, also doesn't count.
Kenshiro's uncle and namesake, Kasumi Kenshiro, from Fist of the Blue Sky, was also prone to arrogance and overconfidence. Well, at least the latter doesn't shows too much.
And Tetsuya from Mazinger Z and Great Mazinger is the deconstructed male example (predating Asuka for twenty years). Also known as Tetsuya "Combat Pro" Tsurugi, he was an orphan kid trained since he was a child in martial arts and piloting Humongous Mecha. Don't you dare questioning his skills and his Ace Pilot status unless you want to make him mad. Don't try to show him up unless you want make him MAD. And when he is angry he can be a world-class jerk. Later you find out that he is so arrogant because he tries to hide he has a HUGE Inferiority Superiority Complex and an utter lack of self-steem. Nevertheless, all of that arrogance and underlying confidence and abandonement issues caused MANY troubles throughout the series.
Balsa's self appointed rival from Seirei no Moribito is one of these. It turned out he overestimated himself a bit.
The son and father who get involved in the wrestling celebration in the village are another example. Ironically, neither of them are even all that good.
Takeshi Onimaru in Yaiba, before and after his transformation. Also Gekkou the Black Moon Bunny and Budou the Grapefruit Soldier.
Homura, even moreso. When she actually bothers to fight, she neutralizes powerful witches and Magical Girls without even trying, and acts astoundingly condescending most of the time. Subverted; she does all this for the sake of protecting Madoka, not because she wants to. Her Hidden Heart of Gold comes out near the end.
Kyo Sohma from Fruits Basket fits this trope almost perfectly. He is a loner, being cursed by the spirit of the cat of the zodiac, and he loses his temper constantly. On top of that, he trash talks Yuki Sohma whenever he gets the chance and spent tons of time up in the mountains training with his master to one day overcome Yuki in a fight. Yet, Yuki remains the stronger, better fighter throughout the course of the series.
Musashi gets the most spotlight, but he is not even the worst example. Many of the fighters of the series – particularly the younger ones – are this to some degree. Gion Toji is a particularly bad case. He believes himself second only to his master, Yoshioka Seijuro, and is an insufferable Jerkass with a constant Smug Smile on his face, who takes pleasure in curbstomping outmatched opponents.
In a bizarre case of this trope, Sakurai in Cross Manage believes that any time someone could possibly be competitive about something, they should be, at least at the beginning of the series. Indeed, he applies this mindset to the concept too, looking for people to deride for playing just for fun or continuing to practice something if they're not good at it. Sakurai does not have many friends, and this seems to be how he prefers it.
Lady Shiva. She occasionally can be cajoled into training promising fighters for good or ill, but her main life's work is to hunt down the best martial artists in The DCU and beat them to death in single combat.
Marvel Comics' Moving Shadow is, at the very least, equal in skill to his brother, Shang-Chi, the Master of Kung Fu. Unlike his brother, however, he never learned the path of peace, and is controlled by his anger. He's also straight up evil, and wants to kill (and, more importantly, defeat) his brother more than anything.
The Mandarin's son Temugin is the Mandarin minus everything except the martial arts skills and superiority complex.
Akira Yamamoto from Hsu and Chan comics is an Arrogant Video Game Designer, who nevertheless fits this trope like a glove. Mainly because he's also a talented martial artist. He and his father are rivals to the titular Tanaka brothers, and their rivalry that has gotten very physical in the past. Like when Akira cut Hsu's hand off in a swordfight.
Davos, the Steel Serpent, from Iron Fist comics. To him, there is no defeat. His alleged loss to Wendell Rand? Slanderous lies. His inability to contend with the fully realized power of the Immortal Iron Fist? A fluke. To hear him tell it, anyway. While he is an incredibly talented martial artist with the sacred power of the Serpent Sting, he wants nothing more than to kill Iron Fist and prove once and for all that he's the best there is.
Richard Dragon, in his latest series. The first issue opens with him winning a pit fight against two opponents, mercilessly killing one of them, and leaving the other alive to spread the knowledge that Richard Dragon is the greatest master alive. His narration remarks that "even those who win money off me do not cheer", because his brutality is too much for an underground fighting circuit.
A Howard the Duck story entitled "Quack Fu" showed an AKFG putting a fatal beatdown on a hyperactive kid who made playful moves against him. Howard gets dangerous on his deserving ass.
Gold Digger is rife with these type of characters, they make up the majority of the series' antagonists. Even the main characters, such as Brittney, aren't safe from this.
The alternate dimension of Jade appears to have an Arrogant Kung Fu Guy-based economy and be governed by an Arrogant-Kung-Fu-Guy-ocracy.
The Wolverine villain Mr. X joined Norman Osborn's incarnation of the Thunderbolts because just killing all comers in underground fighting matches in Madripoor wasn't challenging enough anymore. He was enthusiastic about invading Asgard because he wanted to prove he could kill a god with his bare hands. He could, and he did.
In the Firefly fic Forward episode "Mosaic," the crew has to deal with an enemy pirate gang that includes an arrogant martial arts master named Si Quan. He considers River to be a Worthy Opponent who he can test his skills against, but River disagrees. When he goes after her, she shoots him twice in the head.
Just how arrogant is Tai Lung in Kung Fu Panda? When he meets the Furious Five, who had just cut the rope bridge he was on and were holding it up just long enough for Tigress to get off it and drop him, his first move is to use the rope bridge like a lounge chair while asking where the Dragon Warrior was and then mocking the Five when he reveals that he knows that none of them are that warrior.
Master Tigress flirts with kung-fu arrogance but in the end, is closer to a subversion. She will gladly tell you that she has much to learn and does not boast about her skill. However, in the face of someone like Po, who possesses none of the skill or finesse that she has spent her life perfecting yet is supposedly The Chosen One in spite of that, she will speak her mind and some of this leaks out.
Many villains from Kung Fu movies fit this trope, particularly the Beast from Kung Fu Hustle and Han from Enter the Dragon.
Another would be Sho'nuff from The Last Dragon, who even has a gang/chorus following him around repeating how great he is.
Parodied to great effect in Kung Pow! Enter the Fist, with "Wimp-Lo" constantly challenging the hero. As his master "purposely trained him wrong, as a joke". He believes that losing is winning, and as such his abilities range from "my nuts to your fist style" to declaring: "I'm bleeding! Making me the victor!"
Sonny Chiba portrayed his real life master Masutatsu Oyama this way in Karate Bullfighter, Karate Bearfighter, and Karate for Life.
His character Terry Tsurugi from The Street Fighter series also qualifies, a viciously brutal antiheroicbadass with absolutely no qualms about killing opponents in bloody and painful ways.
The Cobra Kai dojo from The Karate Kid. No mercy, and all that. Oh, and karate is about winning. Don't be afraid to sweep the leg even if you risk disqualification.
Chozen from Part II.
In Crouching Tiger, Hidden Dragon, Jen fits in this trope to an extent, particularly in the latter half of the story. She has The Gift of the art of Wudan, uses it arrogantly, and treats a lot of people she meets as enemies. Granted, she isn't a guy, but otherwise fits this trope for the aforementioned reasons.
In Samurai 3: Duel at Ganryu Island, this is how famous real-life samurai Kojiro Sasaki is portrayed. Hero (and more famous real-life samurai) Miyamoto Musashi, something of an Arrogant Kung Fu Guy himself in the earlier films, completes his transformation into a Martial Pacifist as a result of their climactic duel.
Number One, the Centipede, in The Five Deadly Venoms. Of the six students of the Poison Clan, he's easily the most self assured, feeling that as the first student he's the one in charge and bearing an intense grudge against number five, the Toad, after being defeated by him. He's also the one with among the most impressive abilities; They call him the Centipede because he's faster than greased lightning.
Several in Master of the Flying Guillotine, including "Wins Without a Knife", the dishonest Japanese fighter who, when outclassed, invariably pulls a knife on his opponent and kill them, and the titular Old Master wielding the Flying Guillotine himself, who searches far and wide for the One Armed Boxer to kill him as revenge for a loss that wasn't even his.
Apollo Creed from the Rocky series fits this trope to a T.
Clubber Lang is probably a better example; With Apollo, he clearly had a life outside the ring. Lang knows nothing and cares about nothing but bringing the pain and proving he was the best all along.
The Kurgan from Highlander definitely comes under this heading. He openly admits that he only seeks to kill all of the other immortals, and only deals with mortals for convenience/amusement, but is described as "The perfect warrior" by Ramirez.
Jet Li's character in Fearless starts off this way, before he accidentally kills a master martial artist and wrecks his best friend's restaurant, followed shortly thereafter by the posse of the former killing his family in retaliation. He then has a Heroic BSOD and reforms.
Darth Vader, in both Star Wars trilogies, shows many of these qualities (lacks respect for authority, resorts to violence with minimal provocation, etc.)
Especially Vader-before-he-was-Old-Buckethead, as depicted in the Revenge of the Sith finale (during his climactic duel with Obi-Wan on Mustafar) fits this trope to a tee.
The more so Darth Maul. If you count in the EU background, the latter exemplifies a training style given to Sith deemed less gifted, in which they're taught little but martial arts and using the Dark Side to enhance aggression and physical power, intended to produce shock troops and disposable assassins. At times there have been a lot of these.
Kelly Stone, played by Joe Piscopo in the film Sidekicks, is an example of this trope taken to ridiculous extremes. He even mouths off about Chuck Norris... to the man's face.
Uri Boyka from Undisputed II Last Man Standing movie considers himself "the most complete fighter in the world" and is just as skilled as he's arrogant. After having his knee snapped in the climax he takes a turn towards Warrior Poet in the third one.
In Shaw Brothers wuxia Soul Of The Sword, the nameless hero is this to the core, irritating practically everyone in the martial world by challenging famous swordsmen to duels...and killing them. Amusingly, he is repeatedly told that he is not, in fact, arrogant enough.
In Inheritance Cycle, Vanir plays this role, though in this case the art in question is sword fighting rather than kung fu.
Sisterhood Series by Fern Michaels: Harry Wong is the second greatest martial artist in the world (regrettably, the identity of the greatest martial artist in the world is never given). On a personal level, he acts like this. Fortunately, his relationship with Yoko Akia (the only person to beat him and the only person he fears) seems to have a civilizing influence on him.
A common trend in David Gemmell's writing is the flashy arrogant guy who is convinced he can take the less flashy hero, and who usually has a friend who advises him not to bother. The archetype, Dorian in Legend, goes down in one hit from Snaga.
Live Action TV
Mordred in the 1998 miniseries Merlin. The first we see of him is practicing archery with a group of servants standing with apples on their heads. "If you gentleman don't stop trembling, I might miss and kill you all!"
Dungeons & Dragons 4th Edition has a whole class dedicated to the concept. The Battlemind is a psionic swordsman whose powers act as a form of wish fulfillment, and whose blade is an extension of their ego. Many of their powers revolve around berating enemies for their lack of skill so convincingly they actually become less skilled. Or just die from terror at your abilities
There's even a Battlemind Paragon Path called "Steel Ego", and it's perfectly possible for a Battlemind character to not know they have psionic powers and simply believe themselves to be that good.
It depends on the player, but about half the fluff for the Monk class falls in this category; the other half goes into Dissonant Serenity.
Many "Pro" gamers tend to be like this, in part due to the GIFT. Good at the game, yes, but with a terrible attitude, often veering into Social Darwinist level. The ninth wonder of the world could easily be how they manage to even have friends to play with in the first place. See also “Stop Having Fun” Guys - partly induced by the GIFT. (as acting this way in real life typically results in either you receiving a kick in the face, or people deciding "screw you")
Subverted by a lot of people who physically attend gaming tournaments. Plenty of them are actually good competitors.
Gato and Shen Woo from the The King of Fighters series both fit this to a T, despite not resembling one another much in personality. Gato, in particular, is probably the example, from the way he speaks to the way he dresses to the brutal way he fights.
Adon stands right up there with Gato as a definitive example, however. He has nothing but contempt for anyone, his moves are extremely punishing, and he will not stop until he's defeated every last person who might even kind of be able to challenge him. Unlike most examples of this trope, Adon can often beseen smiling... and it's much creepier than if he were to scowl.
Better yet, it's implied he fought Akuma.
On the other end of the scale and the tier list, Dan Hibiki is a parody of this - he has all the traditional traits of the Arrogant Kung-Fu Guy, with one exception - he's hilariously weak, which turns his bravado into a massively ironic joke.
Especially in Street Fighter 4, Dan is more of a mind game character who has a brutally effective counter super with unreal priority. Beat Dan down enough and he can unleash and turn the tables, turning him into Crouching Moron, Hidden Badass. Even in prior games you could pull it off, it just took a lot more skill.
Just as Fei Long is Bruce Lee, Gen comes off as Pai Mei. Which is interesting since he predates Kill Bill.
Pai Mei, aka Bak Mei, et al, has his roots as a semi-historical Chinese figure. He even founded, influenced, or is credited with the creation of the actual kung fu style, Bak Mei; White Eyebrow. The Pai Mei in Kill Bill was based on Pai Mei from earlier Shaw Brothers movies.
Rufus, an arrogant fat guy who proclaims he's the best fighter in America (Though he actually could back this up), and searches for Ken, without knowing who the guy even was.
Played with in Super Robot Wars Gaiden, with one of Elemental Lord Masters: Hwang Yang Long. Maybe he does not have the loner intent and aggravation, but he's still pretty distant compared to the other Masters, and he's more like The Lancer towards Masaki. Guess what's his occupation: Chinese PE teacher that knows Kung Fu.
And Paul Phoenix is a non-kung-fu example (his fighting style is based on judo).
The Last Blade series has a few. Lawful Stupid government agent Keiichiro Washizuka is extremely self-sure, with the skill to back it up, and has very little in the way of people skills. The series' protagonist, Kaede, has some elements of this normally, but is a much better example in his Super Mode.
Genjuro Kibagami of the Samurai Shodown series is always angry, has an intense rivalry with Haohmaru, and is just a sociopath in general. The only time he ever seems to enjoy himself at all is when he's cutting someone to shreds.
Thing is, Haohmaru himself is as well. He's more gung-ho and optimistic about his place in life but he's definitely got the personality of an AKFG.
Also from the Samurai Shodown series is Wan Fu, a gigantic Chinese royal who believes the path of the sword is "Possessing absolute power to crush his enemies." His character bio states he can kill a tiger in under three seconds, and that he insists he has no flaws and idolizes no one.
In Jade Empire, practically anyone who follows the Way of the "ClosedFist" including, potentially, the player character. This is only usually the case, however, and adherents of the Way of the Open Palm can also act this way.
The Shaolin monk Chinnen from the Power Instinct series of fighting games, by virtue of being an intentional subversion of the Martial Pacifist mold and an amoral egotist with incredibly intense moves. He's more explicitly evil than most, too.
Ghost Kick, from the fighting game Martial Masters, is a despicable misanthrope with an insanely brutal fighting style trying to beat the (supposed) fact that he's the top fighter in the world into everyone else's skulls.
Evil Genius: Jet Chan is a perfect example of this trope (in addition to being an obvious dual Shout-Out). The only way to beat him permanently is to drug him so he loses a fistfight with one of your ninjas. He is so humiliated he never returns.
If this picture◊ is anything to go by, it at least suggests Red has the potential...
Real-life skater Tony Trujilio is portrayed this way in Tony Hawk's American Wasteland; He constantly condescends to the player and kicks your ass if you beat his challenge.
Mortal Kombat's Johnny Cage. He's a somewhat mild example, and his arrogance is somewhat justified by the fact that he's a Hollywood actor, and thus is fairly superficial. Kobra on the other hand is definitely this.
Ezio from Assassin's Creed II starts off as this, but gets better quickly. The first game only shows a few weeks of Altair's life, whereas the second follows Ezio from the age of 17 to 40, showing us his career highlights. It reaches the point where Ezio refuses to kill Rodrigo Borgia, the man responsible for the murder of his brothers and father, because it won't bring them back.
Bass from Mega Man is what happens when you give one of these an assault rifle for an Arm Cannon.
Mr. X from Kung Fu Master is probably this. He even kidnaps the protagonist's girlfriend just so he can get a chance to show that he is the better fighter.
Seifer Almasy from Final Fantasy VIII. He's one of only a very few individuals in the setting who can use a gunblade, and he and Squall are both "in a class of their own" in terms of fighting ability. Seifer's also a Blood Knight who loves fighting, demands that he be allowed to get the kills in a fight so he can get the XP, deliberately injures his training partners and thinks that he's doing them a favor, and disobeys orders to charge off for personal glory. His wild ways soon lead him to defect to the Sorceress.
Two of the incarnations of Odio in Live A Live are like this. Odi Wang Lee in the Ancient China chapter is the head of a brutal martial arts school, and targets the Master's school just for sport. Odie Oldbright in the Present Day chapter is a monstrous fighter who considers brute strength the only virtue and murders his opponents in order to prove his superiority.
Played for laughs in Saints Row 2-the Big Boss of the Ronin crosses katanas with you. After draining his health, he cries out in a cutscene "You cannot match my skill!" to which your character replies "No, so I'm gonna cheat" and shoots him in the chest. Instant hilarity, followed by more hilarity as you use your cell phone to broadcast his screams of pain.
Franziska von Karma of the Ace Attorney series. Though she practices law instead of martial arts, Franziska is a good fit for the trope. Perfection is the only satisfaction she can understand and she acts condescendingly towards everyone else, both in and out of court.
Her father, Manfred, is probably the best example from the series (as later on Franziska does start to become more sociable, though still relatively harsh towards what she perceives as ignorance).
Yutaka Kazami in Investigations 2 has this attitude towards dessert baking.
Pakku on first appearance somewhat counts as this, but becomes nicer later.
Also from Avatar is Xin Fu, the tournament runner tracking Toph with the more pragmatic Master Yu. The needlessly confrontational part can be seen in how happy he is to get in a Bar Brawl and by this line when he heard Toph may have died in the desert:
Jeong Jeong: (describing Zhao) I had a pupil once who had no interest in learning discipline. He was only concerned with the power of fire - how he could use it to destroy his opponents and wipe out the obstacles in his path.
Aang himself was this as well, being just a child and wanting to always get to the cool stuff. His first attempt at firebending fails because he stopped his "control the fire" to make more fire, and burned Katara.
This seems to only apply to firebending, though. When it comes to airbending and waterbending, he's highly spiritual, and doesn't really like fighting much. And he doesn't like bending earth at all.
Before his Heel-Face Turn, Tohru from Jackie Chan Adventures was a textbook example, being an easily aggravated goliath who could crush the title hero with his bare hands. Hak Foo, who filled Tohru's role as The Brute, is also a fine example, a Perpetual Frowner with martial arts skills unparalleled in the series.
Additionally, late-series villains Strikemaster Ice, DJ Cobra, and MC Fist, Totally RadicalJive Turkeys who learned their moves from the Shaolin before going all Deceptive Disciple on them and eschewing "the path of peace" for criminal operations.
Kyodai Ken from Batman: The Animated Series is one of the only characters who can pose a real threat to Batman hand-to-hand... and would've killed him if Bats hadn't sort of cheated. He's also a complete lunatic who just likes beating people up.
Katarou, the gigantic wannabe ninja from the Teen Titans episode "The Quest", had it all. He bested Robin early in the episode, something only Slade had really ever done before.
Grooor and Ceres from Oban Star Racers. Grooor is an extremely fierce competitor and never lost a race until he went up against Molly. He actualy gave her a head start just to make her defeat all the more humiliating... then tried to kill her after he lost. Ceres, on the other hand, constantly flings insults at his opponent and their entire species and makes them hallucinate with his flute until they crash.
Legend Of The Dragon has Ling as the Arrogant Kung Fu Girl at the beginning. She is pretty violent to her brother Ang, is unwilling to consider the responsibilities of the Golden Dragon, and wants its power, even if she has to take it by force and go to the Yin side (i.e. the Dark side). By season 2, she goes back to the Yang side (i.e. the Good or Light side), and becomes a Golden Dragon herself. She still retains a degree of cockiness, however.
''Tokyo Mater'' has Kabuto, a mean and obnoxious Japanese racing car who likes to cheat his way to victory in every single drift race he's been in, as well as having a tendency to strip his rivals of their modifications after losing to him. Guess what happens to him after he loses to Mater at the end of the short!
Another example would be Chase Young, who is very similar to Omi, and was once even a Xiaolin warrior before turning to the Heylin side.
Lightning Dust from My Little Pony: Friendship Is Magic. Her only real care is pushing herself to the limit, which puts Rainbow Dash, the other Wonderbolt cadets, and even the other Mane Six in danger.