I know you haven't opened critiques on this piece so I'll try and be brief First impression is a massive Wow. I'm not even a massive dragon lover, but this is an eye-catching piece so that's a big plus. I think the detail and vibrant colouring in the face may contribute the most to the initial impression. I've found a few things that seem worth mentioning, the proportioning on the horns on the head seem slightly off, I know the left horn is further back, but would it be that much thinner for the relative distance? I already see my comment is getting massive, I have 3-4 small criticisms on the piece but overall it's genuinely one of the best dragon images...if not images in general, that I've seen on deviantart.
P.S. I do agree it's a bit of a strange swamp, but the floor is wet and the edges of the background slightly hint at it too.