Ermine

Stoats (Mustela erminea) are also called Short-tailed Weasels in North America and in winter, with its white winter coat, it is called an Ermine. The Stoat is a very opportunistic hunter, with its diet ranging from small rodents (mice and rats), rabbits, birds, eggs, even fish, reptiles, amphibians, and invertebrates. It is also an extremely skilled treeclimber, descending from it with its head first, just like a squirrel. Once introduced in New Zealand as a means to control the rabbit population, it now is considered a pest there, since that did more harm than good. The term 'ermine' is also used for its fur, for which they are hunted in some areas. In the wild they are found in the north temperate regions of Eurasia and North America. Picture of the stoat by BozMo, licensed under GFDL