Tales Of MU has recently introduced Vice-Chancellor Edmund Embries. He seems to be a classical Western dragon with silver scales, capable of taking on human form—the only form in which he's been seen thus far. He's very charming, very pretty, and very creepy. As Professor Hall says, "Few people mistake a noble dragon for a nice one more than once."
While they don't yet seem to have seen a 'real' dragon, the Whateley Universe has already featured a few variations on the theme. One student has a pet dragon (named Pern, of course) who's apparently a product of her manifestation power and can grow quite a bit in a hurry from his normally small-and-cute stature if bothered. At least two characters, one a student, are known to be hosts to dragon spirits, and then there's Tywyswyr...who, if readers can believe his tale, is actually 'just' a very dragon-looking alien who's nonetheless quite wealthy and apparently a not-so-minor political player living right in the US.
In Addergoole Dragons are evil, shapeshifting faeries who eat people.
Glaserwyrm and Lord Dragon are both mythical beasts who take part in the "metahuman community" of heroes and villains; Glaserwyrm as a villain, and Lord Dragon as a hero. They are both the last of their kind. Lord Dragon has learned to change into a human being, while Glaserwyrm just doesn't see the need.
Draco is a mutant hero who can transform into a classic western dragon. The aforementioned Lord Dragon treats him like a favorite nephew.
The flash game How to Raise a Dragon has players control a Dragon through various stages of life, determining it's breath powers, it's morality and the relationship between the Dragon and a "Hero". The Dragon can either be some kind of Evil Overlord, Good/Neutral Overlord or some kind of Heroic Neutral, using it's powers in various different ways (Using it's healing to help humans or raise a Zombie Army, for one).
Angel Of Death features talking, Western Dragons as servants of the Underworld. These dragons have the ability to effect the weather of the entire planet they visit, with an ice-breathing dragon cooling the Earth so rapidly that homeless people are seen freezing to death outside after two weeks... in California.
The entire point of Dragon Cave. Besides the fact that they need views to hatch, which is a medium restriction, they have a variety of general styles: Easterns, Westerns, Wyverns, Serpents and more. Breeds range from relatively tame concepts such as 'White' and 'Red' to 'Guardian of Nature', 'Terrae' and 'Sweetlings'.
A skull eastern dragon appears in Chaos Fighters and it spits acid. It is the only animal that has its own type of aura element.
Neopets has four dragon-like Neopets: The eastern/western mix Draik, the Extreme Omnivore Skeith, the non-fire-bbreathing Shoyru, and the Scorchio, which are more heat-resistant than the aforementioned three. There are also various dragon-like Petpets like the Kazeriu, which is based on eastern dragons.
Raising Angels: Ever heard of a dragons invading your dreamscape and turning you into an angel? No? Well, Lisbeth have.
In the online Spec Evo project A Scientific Fantasy, wyverns exist although they are called Draks. Many other species fall into the Drak family including Hydra and Kasai Rex. Only True Draks can breath fire, although this ability is only ever really used in courtship rituals. Draks are not sophonts and they only have four limbs, for hexapodal vertebrates never evolved upon Omnia Sanatem.
SCP Foundation: SCP-1779 are a species of tiny city-dwelling reptiles who make their nests out of coins and eat valuables. Given the opportunity, though, they can grow really big, and they desire more and more valuables as they grow.
In Joschua Knuppe's "Skuntabria" project: , dragons are non-sophont monitor lizards with wings. Due to the standpoint that the author about myth vs. reality, they're only marginally like the dragons of myth. They all have two legs, but can walk on all fours, using their wings as forelimbs. Instead of fire-breath, they have a cytotoxic venom that causes chemical burns. They're relatively small, with the largest one being about the size of a horse.
Courtesy of Ken Shardik, dragons exist in both sentient and nonsentient varieties on Pendor. They apparently outwardly follow the 'Western' model, but are genetically engineered lifeforms with likely a hefty side order of nanotechnology like most Pendorians and are at least somewhat solar-powered; in one story, a fairly newly-decanted sentient dragon not yet really aware of that crashes when pushing his limits too far by trying to fly at night.
In the story Dragon! as published in the Guild Companion a dragon extorts cows from a barony. It turns out the dragon does need them for food - even though meat is poisonous to him. It takes a village girl to make him realize he needs something else than just the cows. As the dragon feeds on the milk and the cows dry up after a few months, what he does need is a couple of bulls to keep the cows giving milk...