Ermine

From MiddleWiki

1. A small fur-bearing mammal of the weasle family prized for it's fur. In winter an ermine's fur turns white except for the tip of the tail which remains black. When the winter coats of ermines are sewn together the result is a white fur with black spots spaced evenly throughout. As this was an expensive type of fur (requiring so many of the small animals) it became indicative of wealth and nobility.

2. An heraldic fur. For example used in the device of the Barony of Flaming Gryphon.