1. Someone who plays in the snow or sleds during the ski season instead of doing a real winter sport ie. snowboarding or skiing
2. Someone who drives all the way up to the pass so they can play in the snow, usually annoying to real snow-sport participants, usually takes up alot of the good parking so snow-sporters have to walk extra far with heavy equipment.
"Dude. There's no place to park up here."
"Yeah all the snow rats took up all the fuckin parking spots!"