A little late for the movie, here's my view of Smaug the dragon when he was still small and nimble. As portrayed my J. R. R. Tolkien himself, Middle Earth dragons have mammal-like external ears and somewhat sail-like wings.
When I don't have the energy or concentration for real animals, I tend to draw dragons. Lots of them, actually.
The wonderful free parchment texture is from Allocer2009: [link]