The detail is striking! The many different techniques you used enhance this. I also admire how you had to employ all kinds of different anatomy to form the creatures in this picture, yet did each body part with excellent proportion.
My only critique is the tree itself. The other parts of your drawing (especially near the bottom and your beings as well) employ a wide range of values and shading which gives depth. However, the tree has pretty much one value and one texture throughout, which gives it a flat appearance. This seems odd when that tree is surrounded by so much depth and detail.