Pretty nice, like all of your stuff :)
My only quips about this one are:
1.) It seems that the arm reaching down to pet the beast seems a little bit short
2.) The minimal or lack of shadow said arm casts on the beast
3.) For being such a big and (most likely heavy) beast, it leaves no imprint on the ground it is walking/standing on. It is simply floating on top of the grass there, it seems.
However, those flaws aside, it is a very nice piece, and I love the way you did the lighting and the trees. They look fantastic.