If you’re using Cycles, you might want to add some real GI as the bridge especially looks pretty flat with what appears to be just AO, or add some more environmental light if you’re using BI.
Either way, you should try to get more contrast via the use of a sunlamp as well, it looks cloudy as of now despite the sunny background. Also, is the Dragon supposed to have something that strongly resembles a whale fin as a tail?