Your dragons form is...all up to....god...its very messy.
Your dragon is also very flat, you need to work on your shading, study dragon faces and anatomy as this would really help you.
As for other issues, the spikes on the back/neck are just ..out of whack..they shouldn't be melting and should be even to allow flow and movement within the dragons neck.
As for another issue there is the horns, they arnt paper pieces sitting on him, they are cylinders and they are right on the central points of his body thus some small curve is possibly expect just to give it more form.
I also drew over your dragon just to give you a basic idea of a suggest form.
Thanks all to both of you
I know the shading is bad and the dragon looks flat. I've tryed to paint a dragon on paper, that went out much better, whit both shadows and uuh... flatness. I will try upload it later, if i cant get a scanner
Edit: Another dragon, also made in paint, made for testing where shadows seems to fit.