Hah, very nice. The rhino looks awesome. As for the box, well that is an easy fix, and I am surprised no one has suggested taking a box cutter and simply cutting off the sides. Seriously people, come on!

Anyway, you can then glue your cardboard onto some foam core or wood and use it as a terrain piece.
Adding guys would definitely add to the scene though. Keep up the awesome work!
Or better yet, leave the chimera box, mount it on a larger piece of wood/foam core and get some stuff to make a hill going up. That way you'll cover that box up and have an awesome terrain piece.