Archipelago: Dragons can switch at will between human form and a huge winged lizard form. The lizard form does most of the traditional dragon things, like flying.
Charby the Vampirate: Dragons live near humans and enjoy human entertainment and amenities since they can pass as human if they so desire. While they seem to have plenty of half-elf offspring most of the denizens of Kellwood distrust them, with at least one society having hunting down and killing a dragon as a required rite for boys to enter adulthood.
Dark Wings has the gargantuan Great Dragons, the never-seen-on-panel common dragons, and the small but crafty wyverns. All have approximately human intelligence.
Daryl and Susie: Daryl is a dragon. He, and other dragons like him, is bipedal, is about the same size as a human and resembles a crocodile with wings. One trait that Daryl doesn't share with his fellow dragons though, is that he has monsters come out of his head.
Debugging Destiny has them, in theory. Dragons are remnants of the world before. They are described as enormously strong, with scales that can stop any conventional weapons. The way they are drawn, they may edge into Draconic Abomination if their legs really are as tentacular as depicted. We finally meet one when Ignacia shows up, who adds Hypnotic Eyes to the mix as well.
Dominic Deegan has dragons as well, but only one ever shows up. They're more along the lines of western dragons in appearance, as well as colossal in size and capable of powerful magic. Apparently their language and beautiful and lyrical to the ear, but the one we see speaks a very different language so Dominic never gets to hear it himself. Plus, they're very rare, so if ever one has the opportunity to meet one is considered incredibly lucky.
Dragon City has bipedal dragons who are roughly human-sized and live underground, typically underneath human cities. At least until the Ambis disintegrated the human population of Chicago and the dragons moved in. Also they coexisted with the dinosaurs and started hiding underground before the asteroid hit. Their fire-breathing has atrophied over millions of years, they have the glands that produce it but if they try breathing flame they burn their throats so many have their flame-sacs removed as hatchlings.
Erfworld: "Dwagons" are, much like the rest of the setting's creatures, essentially standard fantasy creatures adapted for a PG war game. They resemble giant stuffed toys. However, in combat they seem to be about as tough and dangerous as traditional Western dragons. They also seem to be non-intelligent, though its hard to tell with any of the basic troops. Basically only warlords get lines.
Fairy Dust's dragons are very similar to regular lizards in appearance and behaviour. Some species are domesticated and are easy to tame, but they otherwise act like normal animals. Their fire breath, large mature size and some species' wings differenciate them from ordinary reptiles.
The Fan: Dragons are deities. They never appear, but a common depiction of Galion, the Dragon of Light is humanoid.
Far to the North: The dragons fit the Western Dragon mold relatively well, breathing fire, flying on bat wings, and seeking to 'collect' one of the protagonist's nieces to keep as a pet. The fact that they've apparently created the entire goblin race from scratch suggests they have abilities we've yet to see though. It's later revealed that the goblins were actually young boys exposed to dragon venom and they eventually become dragons themselves.
Four God Ranger: The only dragon seen so far is one of the Four Celestial Gods, Seiryu. He, along with the other four gods, has the form of a bipedial humanoid creature that is a hybrid human/celestial god. He also has healing powers and seems to be the defacto leader of the group.
George the Dragon has a dragon named... well, what do you know...George. As far as we've seen he is the ONLY dragon on earth, and he certainly DOES get around a bit. He is the regular 4 legs and 2 wings variety but his wings tend to come and go and will. Also of note, George's diet seems to consist entirely of junk food.
Gunnerkrigg Court has Rogat Orjaks ("horned giants"), which are somewhat human-like and somewhat lizard-like large fliers. They're intelligent, benign, and keep to themselves. There were real dragons, until they were exterminated for showing off a bit too much. They're extinct now, but deities like Coyote could bring them if they wanted to.
"We like to keep a low profile. Best not to draw attention to ourselves, unlike those [common dragons]. And where are they now, eh?" — Kos, Orjak.
The first dragon featured is the Dragon King of Mars in one of the fictional Heterodyne Boys stories. He looks like a robotic Western dragon. Mars, in this story, seems to be inhabited by such robot dragons.
The Great Sky Wurm, originally of the Polar Ice Lords, now battle loot of Baron Gilgamesh. E-frikkin'-normous, but can only fly in the cold.
Homestuck: Alternia is home to a species of dragons called the Dragonyy'yd. They are all telepathic, but are blind until maturity. As such, they sense through smell. These dragons are highly intelligent, and can even communicate with the outside world before their egg hatches. Terezi and her Ancestor, Redglare had one as her Lusus. This came in handy for the former after she went blind.
The Inexplicable Adventures of Bob! posits that dragons evolved from kuehneosaurs. They had an advanced civilization but destroyed it in a war, taking the dinosaurs with them. The survivors became pastoral. When humans evolved and came into conflict with them, the dragons avoided a war with the primitives by leaving Earth for Butane, a planet in the Kuiper Belt. They are part of Princess Voluptua's space empire.
Kay The Cookie Jar Dragon is actually a miniature Cute Monster Girl. One of the characters hangs a lampshade on this, talking about all the things that dragons should be; Kay simply replies, "But I am a dragon", and this is taken as a perfectly good excuse.
Keeping the Peace: Played With. Two of the universes have dragons. Dragons like Stalix are around the size of an elephant at most, can talk, and seem to have average human wisdom. Dragons from Shauns world are the size of a building, dont talk and have such low intelligence that they can be at the beck and call of a summoner. The contrast catches a few people by surprise.
Kill Six Billion Demons: "The Kind People" vaguely resemble wingless European dragons, but they are insectoid, pathologically unselfish, and were originally created as sapient beasts of burden (they were needed because non-sapient beasts of burden cannot travel the King's Road that connects all worlds). Mammon was the only dragon who knew greed, and it caused him to be shunned. He murdered his entire family and anyone else who stood in his way until he outright owned one-seventh of the multiverse. He is now known as the "Grand Dragon", and is a massive beast the size of a house who spends most of his time obsessively counting his immense hoard, although by now he has long forgotten why it matters to him.
The Law of Purple: 'Dragons' are actually higher-dimensional creatures that spend most of their time in another plane of existence.
Lil Char and the Gang: Charmander is disappointed to discover that despite the Char family being considered "fire dragon" Pokémon, he will not actually be a Dragon-type once he evolves into a Charizard.
Charizard: Welcome to life, son. It's disappointing. [beat] Charmander: Wait, but... Dragonite is a Dragon-type and we're not? Charizard:DO YOU THINK QUESTIONS WILL CHANGE THINGS?
Linburger: The dragon was long and looked like an eastern dragon. However, it was just a very big beast and devours anybody caught outside like a western dragon. If you kill one, the body will release pheromones that attract hundreds, so the government just leave them alone to chomp on slum residents until it leaves.
Meadowhawk: The main characters are modern-day dragons, ones who'd rather play CubeCraft than burn villages, and eat tofu stir-fry more often than knights.
The colour coding of dragons appears to have been slightly subverted recently with the mother of the dragon killed by Vaarsuvius turning up. She is quite loving of her (now dead) son and husband, and was apparently "open-minded" enough to tolerate her son having a crush on "a nice green dragon". Her grief over her son's death has led her to a vendetta against Vaarsuvius. However, she's still clearly evil through and through.
Speaking of part-dragons, there's the entire Draketooth family, who are shown to have had a number of unique dragon ancestors at the top of their family mural. These include something resembling a female Yuan-ti or Naga, a humanoid with black scales and wings and a Devil-ish figure with a human head, black scaled body, a tail and a horn (and a goatee). All of the people descended from these three have purple dragon markings on their head.
Ozy and Millie: Llewellyn is essentially a lovably eccentric Englishman — and a wise, kind-hearted adoptive father — in dragon form. Oh, and he's also Really 700 Years Old. "Lovably eccentric" is the dragons' hat in Ozy and Millie. During a family reunion, Ozy won a game by being suitably Zen in his justification for not participating to begin with.
Penny Arcade: One comic involves a calling out Dragaera for its dragons being not-so-different, exotic naming to the contrary.
Planes of Eldlor features five subspecies: Fire, storm, desert, swamp, and riftwalker dragons. Each has distinctive features and abilities, though all of them share the classic "western dragon" appearance of having four legs and large, batlike wings. The dragons of Eldlor are benevolent and intelligent, but somewhat reclusive - though occasional mischevious pranksters like Sukozu enjoy visiting human villages just to "see the looks on their faces."
Western dragons are large, powerful mythical creatures who waged a disastrous war with the sphinxes centuries in the past that wiped both species off the face of the Earth — or so most people think; one dragon managed to survive the war and the hunts, fleeing to Dis with his species last clutch of eggs, and managed to raise another generation of dragons there.
The war was instigated by the sphinxes' initial refusal to give the dragons the enchanted shapeshifting medallions only they knew how to create, causing the dragons — who were being steadily killed off by human hunting and saw the medallions as their only hope of survival — to engage in a series of brutal attacks on sphinx workshops and homes to try to take the medallions by force. These hostilities, driven by the fact that both dragons and sphinxes saw each other as evil and cruel, soon escalated into a war that killed off the vast majority of both species.
Only two dragons have been seen in the comic proper, but suggest a great deal of physical variability for their kind. One, the only known survivor, is a red-and-yellow creature with the typical six-limbed arrangement, Asian-style barbels on his snout and an erect, panther-like gait. The other, seen in a flashback, has a whitish coloration, only four limbs — two forelegs and two wings — a sprawling, lizardlike stance and an elongated, serpentine body, all to an effect reminiscent of medieval depictions of dragons.
Several variants of European dragons existed, including wyverns, lindwurms and tatzlwurms. Like most other variants, they're extinct.
The serpentine, wingless, maned, whiskered and antlered Asian dragons are still around, and are by and large distinct creatures from the Western kind — besides being big, intelligent magical reptiles (or part reptiles, in the Asian kind's case) they don't really have much in common with one another. They generally get along quite well with humans who know about their true natures, and use their innate ability to shapeshift to pass beneath human notice.
Slack Wyrm: Ferragus Slackwyrm is a lazy, uncaring, European red dragon — er, fire drake. His sister Hildegard Gretchwyrm, while broadly similar, is much more serpentine in appearance, has golden scales and horns and rules over a city whose citizens she forces to worship her. According to Ferragus, only other dragons are allowed to know or use a dragon's first name.
Slightly Damned: Dragons are only animals but are among the few animals that can use magic. They come in several different forms depending on their element.
Fire Dragons which resemble and act like classic european ones except they lack wings and are bipedal.
And finally Wind Dragons which looked like a Feathered Serpent with four wings and talons but are now extinct. Instead the much smaller wyverns now take their place.
Although he hasn't appeared in-comic yet, there is also Rynn the flame dragon who is one of the Twelve Guardians (a group of demigods who protect Medius) who can shapeshift into a mortal form and is sapient.
There was a flower-breathing dragon that "terrorized" the Dimension of Pain for a while... until Reakk boinked it.
Aylee also took on a fire-breathing dragon form for a while, as a reaction to being stuck in cryo for months. Most of her forms after that and the one just before it were dragon-like.
The flower-breather was one of three "Dragons of Annoyia". Another one was a nebbishy sort who didn't appear to breathe anything, but was pretty much the embodiment of everything you can find annoying about another person.
Tales of the Questor has old-school Western dragons. However, instead of hatching, they are spawned from some kind of evil meteor. Surrounding animals such as livestock and, later on, poisonous and venomous creatures accrete onto the meteorite, falling into the crater and melting, until the resulting blob of flesh has enough mass to transmute into a new dragon. Also, dragons are lux-proof, and go absolutely berserk if another dragon is killed where they can find it. There are also "bog dragons", which are frogs with dragon-ish tails and wings.
In the now complete The Tea Dragon Society, the titular tea dragons are lap sized, capable of living for hundreds of years, and they can grow magical tea leaves from their horns and antlers.
In the companion graphic novel, The Tea Dragon Festival, tea dragons and dragons (which are closer to common depictions in mythology and folklore) share a common ancestor, and dragons are capable of cognitive speech and the ability to assume human like shapes.
TwoKinds: Dragons are intelligent psychic immortal beings who communicate with mortals using Telepathy and use powerful magic, they can also shapeshift into many forms but they (or at least Lady Nora) usually just change into animals due to not being used to walking bipedally. One person claims also to be in the process of transforming into a dragon.
The Water Phoenix King: Dragons are literally incarnations of wealth; they are born when any mass of treasure is left untended for a long time, hence the reason why they always appear in dungeon treasure rooms — they ARE the treasure.
Whither: Dragons are extinct, except bookworms — tiny, slightly glowy, voice-mimicking pests that nest in paper.