try fine tuning the features and details a little bit. Right now it looks too organic. Use some reference photos of dinosaurs or birds and give more detail to his legs. Right now it looks like all it has is a thigh and a foot. Also, the claws seem to just be extensions of his feet. Create some form around them where they come into the feet so that they look like they're growing out of them rather than just being part of the entire foot.
Shiny is nice but not always necessary. A common misconception among new modelers is that everyone likes to make everything either highly reflective or over shiny. Again, look at some animal reference photos and pay special attention to their skins. I would suggest reptiles in your case.
The saddle is kinda kewl, but again, bring out some more of the details. Make the seat look like its been attached to the saddle, not a part of the whole thing. Instead of those hanging flaps, perhaps some stirrups would be nice? And your rider is going to need some way of controlling the beast. Add in a bit and some reigns for the animal.
Professor of Digital Arts
Digital Media Arts College
Boca Raton, Florida