In the Slayers universe, the "demon race" and the "godly race" are vying for control of the world. The godly race usually take on the form of Western-style dragons, but can assume human form if they so wish. Filia, a character from the third season, is a Golden Dragon that apparently isn't much used to her form as a blonde human female — her pointed tail frequently pops out from under her dress whenever she's emotionally excited (which usually tends to happen when she's in the presence of The Trickster demon, Xellos).
Technically, Filia isn't a god herself. The Shinzoku do often resemble dragons, but actual flesh-and-blood dragons like Filia are just a mortal race that serves them. Which explains why they're so much weaker than their supposed opposite numbers, the Mazoku. The novels themselves state that dragons are far, far outclassed by Mazoku. It's actually a minor plot point in the seventh novel.
The Golden Dragons are special. Lina mentions in NEXT that Golden Dragons are some of the smallest dragons, but also one of the most magical and most intelligent. Dragons of other species they come across in the series seem to be little more than big lizards with wings and (usually) some sort of Breath Weapon, while even Lina would hesitate to go up against a Golden Dragon. That said, even regular dragons are intelligent enough to communicate with one another. After Lina is referred to as the "Dragon Spooker" a couple of times and browbeats an explanation out of someone (viz. her reputation is such that even dragons will step aside when she passes) we're treated to a scene where a dragon comes along and starts wreaking havoc in the village...until it spots Lina and starts trying to leave as casually as possible.
Yu-Gi-Oh! and its attendantCollectible Card Game feature a number of dragons, most famously Kaiba's iconic Blue Eyes White Dragon. Kazuki Takahashi has stated that "anything can become a dragon", and any motif can work so long as it shares the most basic, recognizable aspects of dragons, which has led to the most literal interpretations of this trope in fictional history.
In the Yu-Gi-Oh! anime, two of the three Egyptian Gods are dragons and three of the most five powerful monsters are dragons (Dragon Master Knight, Five-Headed Dragon and Malefic Truth Dragon).
In Yu-Gi-Oh!: Capsule Monsters, the fifth Trial is about slaying the five evil dragons Tyrant Dragon, Luster Dragon #2, Serpent Night Dragon, Aqua Dragon and Meteor Dragon, who later fuse to become Five-Headed Dragon (despite that Aqua Dragon is technically a Sea Serpent-type monster, so the fusion is technically illegal). Yugi and his friends get also dragons: Yugi has temporarily the Blue-Eyes White Dragon, Jonouchi has Red-Eyes Black Dragon, Anzu has Seiyaryu, Honda has Thunder Dragon (which is technically a Thunder-type monster) and Sugoroku has Curse of the Dragon.
Many trump cards of the Yu-Gi-Oh! GX characters are either dragons or have "dragon/dragoon" in their name or actually resemble dragons.
Yu-Gi-Oh! 5D's has the Signer Dragons, the main and signature cards of the heroes. They are Stardust Dragon, Red Dragon Archfield, Black Rose Dragon, Ancient Fairy Dragon, Black Feathered Dragon and Life Stream Dragon.
Yuma from Yu-Gi-Oh! ZEXAL has Number 17: Leviathan Dragon, a monster that can power itself up twice, and ZW Tornado Bringer. Kite has Galaxy-Eyes Photon Dragon and his upgrade Neo Galaxy-Eyes. While not technically a dragon, Shark's Shark Drake is very draconian. Kaito's Robot Buddy Orbital 7 uses a deck with an XYZ called Googly-Eyes Drum Dragon, which is also incredibly powerful, but technically a Machine.
Yu-Gi-Oh! ARC-V largely focuses on dragons as well. We have Yuya's Odd-Eyes Pendulum Dragon, Beast-Eyes Pendulum Dragon, Rune-Eyes Pendulum Dragon and Odd-Eyes Rebellion Dragon, Yuto's Dark Rebellion Xyz Dragon, Yugo's Clear Wing Synchro Dragon, Yuri's Starve Venom Fusion Dragon, and Jack's Red Wyvern and Scarlight Red Dragon Archfiend. You can also count Constellar Ptolemy M7, who is very dragon-like despite being a Machine.
Yu-Gi-Oh! VRAINS has Firewall Dragon for Yusaku, and Revolver's varied Dragon deck. Revolver has three ace Dragons, though only one (Borreload) is an actual Dragon-Type, the others are Machine (Cracking Dragon) and Cyberse, like Firewall Dragon, (Topologic Bomber Dragon).
As do Duel Masters and its CCG. Shobu's signature card is Bolshack Dragon. Worth noting is that there are four types of dragons, including zombie dragons, not to mention "wyverns" that look like dragons but don't count as them (uh...), "Dragonoid" lizardmen, and giant reptiles called Dune Geckos. This was a CCG that was fond of horrible, destructive, scaly things.
Record of Lodoss War has at least three distinct "flavors" of dragons. Wyverns are small (read: elephant-sized), unintelligent, non-fiery, two-legged dragons that are domesticated and flown by knights. "Common" dragons are bestial, apparently wingless (there's only one shown so it's hard to judge all of them), huge fire-breathers. The Great Dragons, of which only five exist, are monsters the size of mountains with incredibly vast powers of intelligence and magical skill and close ties to the gods, who guard legendary treasures. The intro has a point that scales Humans to Wyverns then to a Great Dragonnote it starts at about 43 seconds in.
Dragon Half features Mink, a half-dragon girl with horns, tiny bat wings on her back (which somehow let her fly) and the ability to breathe fire. Her mother is portrayed as a shapeshifting red Western dragon.
Delicious in Dungeon has various types of dragons of different sizes and strengths, that live below the earth in the titular dungeon. The Disc-One Final Boss is a large, powerful red dragon with no wings.
Dragons in Naru Taru are about as different as they can get: baby planets shapeshifted into vaguely starfish-like flying immortal monsters with the power to duplicate any object they come in contact with who need to fuse with a human (or other intelligent lifeform) host then join with another dragon/human pairing to grow into an actual planet. And the series is still chock-full of traditional dragon lore symbolism.
In The Five Star Stories the word dragon is best read as "mysterious alien god". Despite looking more or less like typical European dragons with a few more Eastern influences & some vaguely insectoid characteristics & pretty much living like animals most of the time, they are superintelligent & telepathic (even being able to hack computers with their minds) & breathe quasars instead of fire. It is said they are actually a form of Organic Technology Superweapon created by a lost civilization. Luckily for the humans, it seems they just want to be left alone.
Lyrical Nanoha has Friedrich; a cat-sized silver dragon whelp (Wyvern-type body) that can grow to adult size when Caro unseals him, and Voltaire; a Kaiju-sized, humanoid, ancient black guardian dragon that can launch searing torrents of flame from its mouth and wing tips.
In Fairy Tail, its Dragons are a mix of both Western and Eastern versions, whereby their physical form resembles the Western versions but like the Eastern dragons are highly intelligent and possesses insane amount of magic that overpowers almost all humans.
Dragons were once the dominant species of Earthland who mostly regarded humans as a food source but were exterminated to the brink of extinction by a special breed of humans, dubbed Dragon Slayers, who were taught Dragon Slaying magic by Dragons who believed humans and dragons can co-exist harmoniously. There was a war, set 400 years before the manga, that pitted the dragons who subjugated humans against those who were Pro-humans and their Dragons Slayers. Except for Acnologia, those few dragons who survived lead reclusive lives away from and not meddling in the lives of humans. Only recently has the other surviving dragons become more active, by fostering and training orphans to be a new generation of Dragon Slayers in anticipation of a future war with Acnologia.
All the Dragons tend to vary in personality from what is shown in or described. Grandine was very kind and gentle. Igneel was a strict and harsh but loving parent. Metallicana was a cruel jerk than none the less still took Gajeel and raised him. Zirconis despises humans, eats them, and thinks teaching humans dragon magic should have been forbidden, but is at least willing to converse civilly with humans and will give valuable info. Irene sees humans as less than bugs and has no problems torturing or killing them due to their treatment of her despite everything she did to help them, but at least can show some affection for those who prove themselves like how Zeref did for her by letting her regain her human appearance, even if she couldn't biologically be human anymore. Acnologia attacks all humans brutally on sight and comes off as a beast despite his intelligence because he believes humans are such vermin they aren't worth the effort of speaking to despite the fact he still is human, or at least can return to his human form when he wants.
It's also possible for Dragons to be created artificially. When Dragon Slayers begin to mature and further their Magic, they eventually unlock Dragon Force, which begins to change their body's physiology more and more to that of an actual dragon, including scales and, in some cases, wing-like growths. As they mature more and more, a Dragon Slayer's body and mind eventually starts to become more and more permanently like that of a dragon, usually accelerated by the process of killing other Dragons and bathing in their blood, until they finally become actual Dragons in form unless they have certain antibodies to prevent it. This was how Acnologia, Irene and Elfseria became what they are today, and was why Igneel, Metallicana, Grandine, Weisslogia and Skiadrum sealed themselves inside their children to prevent them from ending up like them by developing those antibodies inside their bodies.
YuYu Hakusho has Hiei and his Black Dragon spirit. It's called the Dragon of the Darkness Flame (in the English dub, at least) and is made of black fire. He usually keeps it sealed in his right arm.
Dragons are apparently little more than very very dangerous beasts in Mahou Sensei Negima!. So far, three? have appeared. One was inside the library for some reason, guarding something. Another got its face stomped on by Kaede for a bounty, and Yue took down a Griffon Dragon with barely any supplies except her magical artifact once she bothered to actually study magic. Sooo... the whole 'danger' factor is highly reduced by the fact that they're not really characters.
Then one showed up, an ancient Guardian Dragon who can match Jack Rakan in combat. Scary. One could argue said dragon wasn't so great after all, when it was one-hit-ko'd by one of the villain's summons, at least until you consider that said summon was using literal hax to write it out of existence. Negima seems to use dragons as a way of showcasing how the characters have grown or how strong they are, as it seems that anyone that isn't at least a fairly important or relevant character very much hesitates to face off against one (Eva actually gets really angry at Negi when he asks early on how much training he'd need to fight one).
Dragon Ball has Shenlong (Shenron), the Earth's dragon and a definite Eastern dragon, with a long, slender body, tiny arms and legs, brown horns, and a green mane. He doesn't seem that great of a fighter, although he has the power to grant wishes if someone assembles the show's titular MacGuffins. His wishes have certain limitations; for instance, he can't grant the same wish twice, and can't completely regenerate someone who's been dead a very long time. He also speaks in an older dialect, which implies intelligence. A dragon named Porunga is seen on another planet who is more humanoid and is more powerful than Shenron, having fewer restrictions on his wishes and being able to grant three in one summoning (Shenron is eventually upgraded to have the same capacity).
In Dragon Ball GT Shenron is corrupted by overuse of the wish-granting and each Dragon Ball turns into a Wicked/Shadow Dragon, most of which were vaguely reptilian humanoids that could cause planets to self-destruct just by existing.
Yi Xing Long/Syn Shenron is a white, tall draconic humanoid with lots of Spikes of Villainy. Rather than possessing Elemental Powers like the others, he represents negative energy overall. However, he also has the ability to absorb the other six Dragon Balls to become Super Yi Xing Long/Omega Shenron, who possesses all the powers of the Seven Shadow Dragons alongside a general power increase.
Liang Xing Long/Haze Shenron resembles a large dragonic-toad who poisons people to weaken them since he himself is very weak.
San Xing Long/Eis Shenron and Si Xing Long/Nuova Shenron are a pair of twins who look like slim draconic humanoids with a slim bodybuild and wings. They control ice and heat and have matching colors to their powers.
Wu Xing Long/Rage Shenron looks like a small humanoid pteranodon, but he can absorb electricity to cover himself by a pink slim armor that looks like a gigantic and fat version of himself. And he's lethally weak to water.
Liu Xing Long/Oceanus Shenron is an ugly, winged draconic humanoid being who can disguise herself as a beautiful woman with blue skin. She controls wind and water.
Qi Xing Long/Naturon Shenron initially appears as a gigantic purple mole with no dragon features whatsoever. After absorbing Pan, he becomes much larger, and becomes a weird mix of a dragon and a blue mole, now having fins on his head and two tails. Besides absorbing living beings to become powerful, he creates earthquakes. His true form is that of a little bit oversized mole.
Finally, Dragon Ball Super introduces the Dragon God Zarama, who created the Super Dragon Balls, which are the size of planets and scattered throughout two mirror universes. If gathered, he will grant any one wish with no restrictions. The other Dragon Balls were made based upon his creations. Super Shenlong is so huge, galaxies look like Bishie Sparkles in comparison.
Spirited Away: Haku AKA the spirit of the Kohaku River is an Eastern Dragon that's able to take on a humanoid form.
Digimon has several species who are considered dragon and are distinguishable by the suffix dramon (although not always, most predominantly in the "Four Great Dragons" family) in their name. Dragon-like Digimon tend to be partnered up with the main character.
Their appearance is also inconsistent with almost anything: Davis's Digimon in Digimon Adventure 02, Veemon, is a humanoid (if rather short) blue dragon-type Digimon, with two legs, two arms and a tail. Guilmon, partner of Takato's in Digimon Tamers, is a red dragon-reptile-like Digimon with two arms with three claws, and two legs also having three claws. Pretty crazy.
One Digimon family, stemming from a squat, four-legged reptilian Digimon named Betamon, is made up chiefly of dragons. Down one line, Betamon can Digivolve into the snakelike Seadramon (a sea serpent, essentially), which can further become the many-finned, horned Megaseadramon, which in turn becomes an armor-plated, Cyborg serpent named Metalseadramon. Down the other line, Betamon can become Airdramon, an amphiptere-like serpent with two batlike wings and no other limbs. Airdramon can further become Megadramon, another cyborg dragon with robotic claws and a metal faceplate. Megadramon further becomes Machinedramon, a fully robotic, hunched-over bipedal dragon. As it happens, both Metalseadramon and Machinedramon were part of the Big-Bad Ensemble in one of the original anime's story arcs.
The "Four Great Dragons" group consists of Magnadramon◊ (who was formerly a cat at one point in its lifespan, and still looks fairly feline itself), Megidramon◊ (an evil final form of aforementioned Guilmon), Goldramon◊, and Azulongmon◊, the last of whom looks the most like a traditional dragon of the Chinese variety. As Digimon are said to be born of computer data about things from the human world, it makes sense that so many kinds of dragons would be present in the series.
In Digimon Xros Wars, Dorbickmon's army is composed entirely of dragon Digimon, except that he expands the definition of dragon to include anything even remotely reptilian. In addition to assorted 'dramons, his army includes Brachimon and DarkTyrannomon, which are dinosaur Digimon, as well as FlareLizarmon and Salamandemon, which are more or less exactly what their names suggest. A Devidramon tries to force Shoutmon to fight in Dorbickmon's army. Dorbickmon even DigiXroses with a Huanglongmon, which is the leader of the Digimon equivalent of The Four Gods in the rest of the franchise, to show off how badass he's supposed to be.
Bleach has Hyorinmaru, a zanpakuto, generated from the soul of its user, and while they provide the majority of abilities for their masters, the Zanpakuto are beings unto themselves, often sharing similar personality traits as their masters, and more than a few seem to represent their respective masters' inner, repressed feelings. Here's an example; being the zanpakuto of Toshiro Hitsugaya, Hyorinmaru is an ice dragon, apparently one of calm, gruff wisdom, while Hitsugaya himself is a mature, but grumpy dude that is actually more emotional than he'd like to let on. While in his human form, Hyorinmaru is calm, quiet and obedient, whereas Hitsugaya is irritable and more prone to temperamental outbursts than his ice dragon mentor.
In Kurohime, dragons are usually golems made from magic bullets. In some cases, they're whales who eat time and freaking fly. However, even the golem type ones are considered as powerful creatures that only strong and skilled mage/witch can summon.
In Rave Master, dragons originate from a dragon clan, which are Lizard Folk until a certain age, at which they either pass a test (and become human looking) or fail it (and turn into a feral dragon.) Appearance wise, they are western four legs two wing style.
The Vision of Escaflowne's dragons seem bizarre to modern audiences, sporting only two limbs (webbed to the bodies like a squirrel, in lieu of actual wings), blade-tipped tails, somewhat pudgy bodies and snakelike heads, but these animalistic, fire-spitting beasts are probably closer to the dragons of traditional Western folklore than just about any other anime. Also, their hearts are used to power giant robots. That part's not so traditional. The dragons shown in the anime are known as chiiryu (literally earth dragons); further reading has it that there are three tiers of dragons — chiiryu, suiryuu and tenryuu, for the land, sea and sky respectively, and that each one is infinitely more powerful than the last. Also, while the chiiryu borrow from western dragons, the suiryuu are more traditionally eastern type dragons (they can be seen in the architecture of Asturia).
Yaiba: Ryuujin the Dragon God is supposed to be the classical, huge eastern dragon. He actually has a human avatar as a badass samurai warrior. His true form is revealed when Yaiba uses the full power of the Orb of Ryuujin.
Several Mechanical Beasts from Mazinger Z resembled dragons, and the aspect and weapons of each one of them was different: Gelbros J3 looked like a bypedal dragon with three heads could shoot heat waves, soundwaves or acid streams: Drago Omega 1 resembled an Eastern, flying dragon shoot missiles...
Combattler V: Kiiru, the "Slave Beast" showed up in episode 9 was Garuda's dragon pet (Let me stress this: Garuda's pet was A FREAKING DRAGON). She resembled an eastern dragon, with antler horns, long whiskers, rectangular snout and a long, sinuous body. She could breath fire from her mouth, shooting beams from her eyes and regenerate herself. And it was a Mama Bear, too.
Sgt. Frog has two instances of dragons, with the main alien cast transforming into dragons with missiles, dragons with energy blasts, even a ninja dragon with a BFS.
If anyone makes the mistake of trying to depower Touma Kamijou by cutting off Imagine Breaker, his Anti-Magic / Power Nullifier right hand, a massive white dragon will emerge. It's implied that this dragon may be sealed by Imagine Breaker, and is released when the right hand is cut off. What is definitely known is whatever this thing is, it's one of the most powerful beings in the setting, to the point it's stronger than a guy who just minutes before became stronger than God.
When this happens in A Certain Scientific Railgun, due to his hand being blown off trying to stop Mikoto's out-of-control Level 6 Shift, the same dragon reappears... along with seven others, each wildly different than the other. Interestingly, in all subsequent occasions when the hand is severed, something only described as "invisible" emerges. It's unclear if this is the same entity as the dragon, and there are hints that they are separate entities.
In the Jailbreaker Arc of Railgun, a criminal esper named Kimi apparently has the ability to summon a vaguely angelic-looking dragon using her right hand, and thanks to the AIM Jammers of the prison couldn't do so until she managed to get out of range. This dragon also looks just like one of the eight that emerged from Touma's severed arm.
References are also made to "St. George's Dragon" by the magic side. The being actually called DRAGON later in the story is, however, Aiwass, mentor of Aleister Crowley and the most powerful being in the series seen so far. That includes the dragon(s) sealed in Touma's right arm.
The first filler arc of One Piece revolves around an elderly dragon, which looks more like a gigantic bird. And that's when it's not curled up into a big ball of feathers, which is the position it spends most of the arc in.
In chapter 655 the crew has now run into a giant western style dragon which can apparently talk. Except it turns out that it wasn't the dragon talking. It was a set of human legs with no upper body or head that can talk and had been attached to the dragon..., thanks to Trafalgar Law.
Later they encounter a small talking Eastern style dragon who is actually the son of the samurai they met earlier. He ate an artificial Zoan type Devil Fruit that turned him into a dragon.
One of the Four Emperors, Kaido, King of Beasts, is revealed to have the power to turn into a massive Eastern dragon.
Demon King Daimao has Peterhausen, a ridiculously large western dragon that breathes drills and missiles.
Drago from Bakugan, who can actually curl up into a tiny ball when he is not fighting.
Well, let's not sugar coat it. This anime is full of this! Dharak, Rubanoid, Plitheon, Avior, Wayvern, Naga, Percival, Hydranoid, and Helios are all dragons or dragonn-like beings.
There are a lot of dragons in High School DXD and are considered to be the most powerful race in-universe. Issei, the protagonist, is considered as one even though he's still a human-devil hybrid (he was killed at the beginning of the story thus reincarnated to a devil) because he has a dragon sealed in his left arm named Ddraig, a Welsh dragon.
Many of the more powerful cards in Cardfight!! Vanguard are dragons, and many characters have used at least one at some point. Most of the Kagero and Narukami clans are outright dragon-themed, and Tachikaze make heavy use of Dinosaurs Are Dragons.
Melan from DokiDoki! PreCure is a fairy who looks like a tiny turtle lady, but can transform into a powerful Western-style dragon. She also defeats the five Pretty Cures twice to test them.
Cross Ange is all about a group of normal girls forced to fight dragons in Cool-But-Unreliable Mecha in a world that HATES them. The dragons as they seem are alien enough, using rifts to cross dimensional barriers and armed with a ranged-biological arsenal that rivals the latest in advanced technology. Then the second half of the anime comes along and it turns out that the miniature dragons are female were-dragons and are biologically compatible with the mega-giant alpha males. Their ancestors genetically augmented themselves after World War 7 and the Big Bad decided to steal their supreme leader for use as a mana reactor, AURA. The kicker is that magic in Ange's world (which hates her because they can use magic and she can't) is powered by none other than the efforts of Ange and company, as killing dragons powers the reactor.
Miss Kobayashi's Dragon Maid: Due to the Fantasy Kitchen Sink nature of Cool-kyou Shinsha'sverse, all of the dragons have vastly different powers and appearances. The only real consistencies seem to be their ability to fly and use magic (generally to turn into human form). It's also important to note that Tohru's fight with the gods and Quetzalcoatl's backstory demonstrates that dragons are the level of power below godhood in the series.
Claymore: In the anime, one male Awakened Being looks like a western-type dragon, but, apart from that, does not differ from other Awakened Beings. Later in the manga it is stated that the Organization created the warrioresses and the Awakened Beings because they were at war with a species of dragons, and needed a secret weapon.
In InuYasha dragons are another kind of youkai, but a very powerful one. Although the strength of the dragon youkai can vary, they are among the most powerful youkai. They are visually similar to the eastern type, but are almost always evil. Although almost all of them have a serpentine body, some of them still have wings.
One of them, Ryukotsusei, was the old opponent of Inuyasha's father. However, this sealed him until Naraku has freed him again. He looks like a dragon of the eastern type, but can spew powerful ball lightning. He also has a mask on his head through which he can speak.
The anime shows some more dragon youkai, which are similar to the eastern type, but like the western type, not very intelligent, and very vicious. But one of them is also benign, and the companion of Sesshomaru.
In Rakuin No Monshou dragons were the native species of the planet before humans settled there and originally intelligent. After their defeat by humans, the dragons became bestial and are now domesticated for use as war mounts and beasts of burden. Individual breeds vary significantly in appearance, shape, and even number of legs but are uniformly ill-tempered and never fully tame. Their fossilized remains are a key component in the setting's magitek airships.