This is a really good work of art, actually. It's nicely done, and it's better than what I could ever do. The background is my most favourite part of this piece.
The colours are great, and I really like how the picture crosses over the black border. Though, the details on the character are a tiny bit blurry. . . Also, it's kind of difficult to tell where the light source is coming from.
I think the necklace should have had a shadow or shading underneath it. That way it doesn't look like the necklace blends in with the character's skin. I think it should have also stuck out a little more instead of being flat and following the curve of its neck. I don't know if my eyes are deceiving me or if my computer's just not showing right, but there's a sliver of white on the right of its neck. Maybe that's part of the shading or technique. . . I can't tell.
The scales on the top of its head should be a bit more shinier, since they are closer to the moon. You did perfect on the ones on the back and the back of its head.
I'm a bit jealous. xD I can never seem to draw backgrounds like that. It looks very realistic, and I think it might even be a photo rather than a drawing since it looks so perfect.
But by all means, this is fantastic. I really love it.