Personal project. Killed my pc with this one.
Cheers!
Very nice work! My computer would never cope with that many hair particles without exploding. Combing those guys must have been a nightmare too. 
Overall my only criticism would be that it looks quite flat in terms of tone. If you had some darker shadows and brighter highlights it would really make the image pop. Maybe play around with the lighting a bit.
Sort of elaborating on what Gibby565 said, another way to make it look more interesting and less flat would be to work on composition. Making sure you have a focal point and proper balance. The models and scenery in this project are far beyond what I think I could do, but it could still look better if you watch Andrew Price’s hour long boring video on composition and then just move things around a little.
these mammoths look good. Too bad the forest, lighting and compositing aren’t really keeping up.