I can't give critique on the dragons 'cuz mythical creatures defy the rules of anatomy,
Kagepen. Here are some links and pictures to help you lrn2anatomy
Sorry about the crappy scan, books are a pain. Anyways the point here is that all mythical creatures are either based on one type of animal or a combination of several. Any artist who knows what they are doing will have studied the anatomy for the creature that they are drawing.
For example:
Serpent dragons you study SNAKE anatomy... Or lizard dragons you study Lizard anatomy. if you want to add wings you study BIRDS....
a mythical creature that doesn't follow the basic laws of anatomy just doesn't look cool. It looks weird and like a five year old drew it.
Everlastin your dragon isn't too bad. it needs work. I'd say if you want it to be serpentine study a snake because right now it's like a salamander on steroids. Which you can work with.
Also have a feng video
http://www.youtube.com/watch?v=dnflBERf2zMSorry the images are so huge.