Gorgeous fellow. Posing on the wood does not really look all natural (I think), but it still looks supreme as far as appearance and reptlie attitude. Well done; now you ought to get one tight head portrait, those spikes would rock up close! :)
TFS
Good pose on him slightly turned towards him. I would have like to see more DOF so that the nose and opposite eye socket were sharper.
I like all that detail so felt some Local Contrast Enhancement on BG copy using USM at 20/50/0 followed up by some additional sharpening would help to accentuate it.
I like the pose and framing Mike !!! Agree on increasing contrast and sharpening ... btw if you were on a tripod might have gone for less shutter speed and more dof Excellent !!!