The Ulfhednar were a group of Viking warriors who originated from ancient Norse religious rites. The Ulfhednar wore wolf skins, and their own skin was black-died. Like the Berserkers, they preformed chants and rituals prior to battle, when, through adrenaline, they became 10 times stronger and faster, became immune to pain, and bled less.
Unlike normal berserkers, these warriors wielded no shields. They eventually merged with the Berserkers in name, yet continued to prefer their own methods.