I had a wander through google on my (semi-mythical) coffeebreak, and discovered this delightful sketch by John Howe (one of the conceptual artists on the LotR movies):
http://www.john-howe.com/fataneh/gallery/details.php?image_id=1432 Everything but the demon's eyes is perfect -- funny how our angel and demon get into the subconscious of the world .... Also makes me wonder if the purveyor of fine leather goods for whom it was drawn carries snakeskin shoes? ;]