The sculpted ridge of central snow left on the roof of a vehicle by someone either too lazy or too short to brush it all off.
I was cruising down the highway behind a Tahoe sporting this ginormous snowhawk when the Tahoe's driver hit a pothole. Like an icy combover on a guy in a convertible, the damned snowhawk grabbed air, flipped back towards me, and I was sure that was going to be the last thing my Prius and I ever saw.