Sand vipers Cerastes cerastes are stand-outs in the snake world for possessing the longest 'horns' of any snake species.   I've heard speculations that they may serve as sun shields to the eyes, or wind / sand deflectors.   I have two of these at home in a large desert vivarium where I am able to observe them frequently.   I wonder if the projections may act like lures in the desert when the snakes are buried in sand with only their eyes exposed.   The stubs may resemble sprouting plants that would attract rodents to a juicy seedling in an otherwise barren habitat.

This straight-on, in-your-face close-up epitomizes "cool" to most herp people, though it may be equally scary to other folks who can't appreciate true natural beauty past their ophidiophobia (fear of snakes).   The adult specimen above belongs to Jessica Upton, a friend who bred and hatched 20 of them in 2003; that's one of them (below) coming out of its egg with its baby horns still folded over.   The lower right pic shows three adults in my home set-up a few years ago.