lol...first off, I named my dragon Draco as well....
Anyways, I built him a 57"x24"x19" viv over the winter and used a couple methods I saw while looking through the viv picture thread. Basically, I used styrofoam from a cooler that was used to transport tropical fish in. I cut it up into big enough sections and glued them together to create a big enough to create a rock-face background for Draco's viv.
Test fitting the size:
After drawing some rock shapes, I tool a dremel tool and a wire brush to gouge the styrofoam and create the rock pattern.
After about 5 coats of grout and 3 coats of shellac, here is the end product:
Very easy and relaxing to do...