I just finished this for this weeks Creature of the Week at ConceptArt.org. Here's the description I posted along with it, hello nerds!
The adage "Every cloud has a silver lining" has not always been meant to inspire hope. There once was a time when the phrase was taken as a grim warning by those who knew. The Silver Teeth of the Storm, as they were called, once plagued the lives of sailors unlucky enough to encounter them. Resembling a flying horse without rear limbs and partially composed of what must somehow have been living metal, herds of silver teeth rode the skies in search of sailing ships. Never far behind these flying herds were the thunderhead of storms. Scholars of the times conjectured that it may have been their metal composition that allowed the silver teeth to seemingly lead and drive the storms. Men at sea would have short warning of their arrival (be it from a silver flash in the sky or the ratcheting whinny of their call) before the clouds burst forth upon them. The silver teeth would snatch away any sailors thrown overboard by the storm, or feed freely if the ship were to capsize.
Edit (from Dan's comment, too cool to pass up):
3 colorless mana
summon artifact creature
tap: deal 1 damage to target tapped creature.
1 blue, 1 colorless: tap target untapped creature.