Overall, great.
When critiquing this, I would only have these two suggestions. The color scheme and shading is nice, and the lines are good for the effect, but I would like to see a bit more detail on all of the dragons, instead of just highlighting the purple one. Also, the only difference in their poses are the way the tail is swished. A bit more variation would put more personality to them and make them seem altogether more realistic, even though it's a hard thing to do in a drawing like this. One's head could be lowered, another could be displaying an expression, small things like that.
As just a regular person, I think it's fine :D