I was actually a bit anxious about finding a suitable model, since gaming dragons tend to be on the pricey side (although the Reaper Bones ones were quite reasonable). I didn't know exactly what I wanted, until I stumbled on this bad boy in a charity shop for £10.
That's all 28mm scenery, for reference.
Now, originally he was blue, so I just slathered him in cheap black craft paint, highlighted some fins and warts and things up to green and gave him a coat of varnish. On the morning of the game, I might add. The paint job isn't going to last, but again, he's hardly likely to turn up again, is he? When you're doing frugal gaming you have to think about how things are going to be used.
Still, I think for £10 he's not bad, especially since he can do this:
Overall, a very satisfying final battle.