Double Trouble

first off very nice picture. You did a very nice job defining the muscle tone of both creatures.
The only critique I can think of at the moment is this:
For the water under the right dragon I would have used a thinner line to define the ripples. The brush you have right now is fairly thick and blotchy. Also on the foot that is lifting out of the water what I would have done to describe the dripping water is actually outlined the dipping water instead of highlighting the middle. As water is "ripped" apart for lack of a better word it becomes stretched and often breaks apart in the middle, making the water very translucent in the middle. What might look better is if you outlined the water then have it fading out toward the middle -no highlights-

For the left dragon his paws look too small for his bulk. You did a very nice job on the other one's feet -size/shape/and all, but spastically the front right -our right- paw seems to small. Maybe just resize it be a little bit -leave the others alone I think. Also stay with the same leg I think the elbow is a bit too low. When an animal is putting a lot of weight on a front leg -like when its walking- that's either right under them or slightly tucked toward their belly the elbow rises and hugs the body more closely.

The shading you did is VERY well done, you seem to have broken away from the outline shading most artist seem so attached to. Now tho I think it would benefit you to experiment with 1 different levels of shading and 2 the gradient tool.

Putting different levels of shading -shading onto of shading- can help give a character true form/depth making t appear alive.

And the gradient tool is very handy to use while creating levels of shading.
I personally use the type of shading you have done, the go over with the gradient tool to go a nice smooth transition from the harsher shading from the basic shade of the original colors. The gradient tool is also great for when you need on side to be darker than the other but you still need the lighter side to be shaded as well.

I highly recommend experimentation with both aspect to give your already awesome artwork that extra boost to make it extraordinary artwork.