Norse Beliefs

In Norse folklore, a skin-walker is a person who can travel in the shape of an animal and learn secrets, or take on certain characteristics of an animal. The person is then said to be wearing that animal's hide. The most well-known example of the latter is the warrior who takes on the strength and stamina of a bear, called "bear shirt" or ber sarkur, the origins of the word berserker; similarly, there were wolf-based warriors, called ulfheðnar or "wolf-coats". They were said, aside from the battle-rage the animal spirit granted, to have the ability to send out their soul in the form of their animal, in a practice called hamfarir or "shape-journey".

The use of an animal shape for other purposes was considered unholy, and people accused of having such abilities were frequently cast out or summarily executed. Females so charged got off more lightly.