First off, this is a really charming picture of a classic theme. I like that the tail and head her turned in opposite directions, following a serpentine pattern which keeps the eye moving. The negative space on either side of the dragon really helps the canvas not feel overcrowded, while making the dragon still feel imposing. This is a refined use of space.

I do wish that there were some more textural variations here. Although the crosshatching gives depth to the tail and underbelly, there is not enough differentiation between the scales of the dorsal area and the crested fin above it. Because the fin appears to be a membrane, it should feel like it's composed of different matter than the other parts of the dragon's hide. I can't help but to feel that the is also missing a wing / wings? This is not an issue if it's intentional, of course, but it's a noticeable absence of a traditional dragon element. Maybe the crest on the back is supposed to fulfill that function, but if so it needs some indication of a joint.

The simplicity of the precipice is a nice touch. I like the jotted tufts of grass and rocks and the fact that their abstraction lets the dragon stand out.

I'm impressed you could carry the drawing so cleanly over a crease in your sketchbook, that is not always an easy feat!