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 we 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 we 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 in the Global Guardians PBEM Universe; 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).
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. Some species are sapient, others only about as intelligent as birds. Some are as tiny as a chicken, others as large as mountains. Some breeds will sooner rip you to shreds than look at you, others will cuddle with you in front of a camp-fire.
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.