Have you noticed that at some point, dragons became the good guys? It’s very much a 20th Century development in western culture. Until probably the 1960s, with Anne McCaffrey and Ursula K. Leguin, dragons were always bad, ranging from (to use the D&D system) lawful evil to chaotic evil. But still evil. Now, we see dragons ranging from practically candidates for sainthood to no better or worse than average to, hmm, I’m not certain how to classify the dragons from A Song of Ice and Fire because so much depends on who is “managing” the beasts.If you go way back in western literature, you find evil dragons in the form of Tiamat in the Babylonian creation story. Tiamat is a creatrix gone wrong, eventually killed by her own offspring. The prophetic books of the Tanach/ Old Testament use dragons as representing something powerful but not always good (or lawful neutral in the Psalms and Job). The Greeks also had an evil dragon, along with sea-serpents and dragons as tools of the gods, sent to punish people. Rome used the Draco as a standard, and I’ve read some very interesting German literary history articles that theorize that Sigfried’s dragon, in the Burgundian Niebelung saga, is drawn from a very highly modified version of the Germans’ defeat of the Romans at the Teutobergwald, with Sigfried standing in for Arminius/Hermann, and the dragon being a reminder of the Roman standards, the dracos.
Modern reproduction of a draco. From: http://www.fectio.org.uk/articles/2005_drum_10.jpg
It makes sense in a way, because Nordic mythology (Wagner’s Nibelung) seems to lack dragons, replacing them with serpents (yes, usually shown as dragons, but there’s a difference in the terms used in most manuscripts. Not all.) The New Testament? The Revelation of St. John is bad dragon all the way.
Medieval dragons are all bad. The Lindwurm in southern Austria, the water wyrms in England, the dragons that try to eat saints (with a notable lack of success. You’d think at some point the pagan kings would give up and stop inflicting indigestion and bad teeth on their lizards) are all evil. Heraldic dragons are a bit different, and the red dragon of Wales is good if you are Welsh, not so good if you are Saxon. Certain monarchs used dragons in heraldry, but it was not as common as lions.
A Medieval illumination from Beowulf. Very bad dragon indeed. http://2.bp.blogspot.com/_MeaQFKuzvXc/TENmGNJMWbI/AAAAAAAAC2M/ferA6hSIezM/s1600/beowulf-wiglaf-wyrm-moralia-job-129rheorotdk.jpg
And then came the 1960s, and while Smaug is one of the great bad dragons of literature, dragons got rehabilitated! You have the telepathic reptiles of Pern, you have dragons scaring their kids with tales of evil Georges, you have dragons slaying evil knights, dragons helping princesses, dragon card sharps, dragons reborn as humans who switch to dragons and discover it’s hard to make a living in Tokyo when you have that problem, and dragons who offer acidic comments and then tell the knights to go bugger off and leave them alone.
At least one of my readers is a dragon (lawful neutral shading to good, as I recall, depending on how his day has been), or identifies as a dragon.
Did authors just decide to flip the old trope? Was it part of the 1960s “subvert all the things!!!!” mood? Was it the dragons of the original D&D, where some are goodish, some are bad, and some are really, really bad (Tiamat again)? You don’t see as many evil unicorns, for instance.
Some years back I read a really well done semi-academic book about dragons in modern fantasy literature (through the early 199s, as I recall) that hit the highlights, focusing on characterization and use of dragons as “player characters,” to borrow again from D&D. Instead of shorthand for “eeeeeevilll!!!,” they became more complicated (not that Smaug is simple) and in some ways less powerful, in other ways more so. I suspect by now, the proliferation of dragons is such that a “real” dragon (lawful neutral) could stroll down a street in LA and most people would just stare, then say “Dude! Cool effects! I wanna see that movie.”
Cat Rotator's Quarterly 
Don’t forget the Chinese Dragons that were basically gods and not “evil” gods.
Eh, unicorns used to be evil also, and have been flipped.
I’m not sure about “unicorns being evil”, but they were dangerous beasts able to kill elephants. Note, some of the older stories about unicorns have them getting several elephants stuck on their horn. 😉
Aye. Unicorns were dangerous… for the “impure” and harmless or beneficial to the “pure”. Then there are the stories of “black unicorns” for what they’re worth. But being at ease at night (in the dark) and experience troubles/problems in the day (light) I have this idea that the general religious idea of “light==good” and “dark==bad” is 180 degrees out of phase and if they get something that basic wrong, well, the rest is at best very suspect indeed.
Part of the “blame” can be laid at the feet of Anne McCaffery. She once said when she wrote Weyr Search that she wanted to show the dragons as being good; to chance their image so to speak. 😉
I guess the rest just kind of followed her. Kinda like how we see “not evil” vampires now days.
Don’t forget that some dragons are/were knights. Sparrowwind’s The Dragon who lived as a Knight and G R Dickson’s Dragon Knight series.
Which shows how far the western dragon archetype/trope has flipped. I suspect we’re at the point where a Smaug-style evil dragon is “new.” (I’ve got a novel in my TBR pile about treasure seekers who discover that “dragon stone” is not a metaphor and the dragons are hungry and Evil. Oops.)