It's a little harder to comment on a fantasy figure like this as who is to say what it really should look like. Overall I would say it is done well. As for what could be improved I'll echo Helm's advice. I think the green skin could use some more color variation. Spots would be an interesting effect. I'd like to see some other colors around the eyes, maybe a hint of blue or red. Keep the green, but use a wash or glaze to give it a little more variation and interest. The ears are another place this might work. These sorts of figures give you a lot of freedom... I might try a hint of yellow around the outside of the ear and some blue in the inside. A lot or just a hint... whatever works for you. You can just push things a little more on the non historical figures.
