1. (common) A hot girl who loves to snowboard/ski, and looks good doing it.
2. (uncommon) A term used by pathetic cuckold-fetish whitebois who get off on the fantasy of white girls humiliating them by saying they prefer black men. It's a humiliation fetish based on a fantasy of racial inferiority.
Damn, I met the hottest snowbunny out on the slopes today! You know how I love a girl who can snowboard.