That's an interesting interpretation of a sea-Dragon you've done there. It's body is Draconic looking, but with fish-like fins (those things on it's back), and the webbed hand and feet. It's left-arm reaching towards the viewer seems to be flat, and gives me the impression if it touching glass - as if it wer confined. Is this the look you were going for, or am I viewing it wrong? If I can make a suggestion - shorten the Dragon's neck. In proportion to the rest of it's body, I feel it is a little long, even for a water-type Dragon. It's wouldn't be too bad if it was based on an Eastern type, as the have long necks, but this Dragon isn't - the body is too big for that (Easterns are very thin) and the back limbs are more of a Western style. I like the colours you chose for when you re-did the head of the Dragon - I think they fit well with the aquatic image.
One more thing I'd like to add - when I tried drawing a while ago, if I made a basic sketch I liked, but didn't want to add any detail or colour to it from fear of ruining it, I'd scan in the sketch, and print off a few copies of it. That way I could have as many shots at it that I wanted. Just thought I'd put that forward.