Granted there probably aren't that many to begin with, but Sir Big Spur makes the list.
link: http://sportsillustrated.cnn.com/multimedia/photo_gallery/1010/ncaa.real.animal.mascots/content.5.html
link: http://sportsillustrated.cnn.com/multimedia/photo_gallery/1010/ncaa.real.animal.mascots/content.5.html