Ermine tail

An ermine tail or ermine spot is an element of a heraldry tincture (in particular, a "fur"). Per Wikipedia, the ermine spot, the conventional heraldic representation of the tail, has had a wide variety of shapes over the centuries; its most usual representation has three tufts at the end (bottom), converges to a point at the root (top), and is attached by three studs.

The coat of arms of the former Duchy of Brittany.