The Ulfhednar of Scandinavia is similar with the berseker in a lot of ways. For starters, they are warriors who wore an animal Skin but instead of using a bear skin which the berserker use, the ulfhednar use a wolf skin. They also believe that by wearing a wolf skin, they were able to channel the spirit of a wolf into their body thus inheriting their abilities such as the remarkable speed and strength. Legends claimed that these warriors do not feel any pain when they are in the battlefield.
Snorri Sturluson described them in the Ynglinga as “strong as bears or wild oxen, and killed people at a blow, but neither fire nor iron told upon them.” It is not clear though how they were able to achieve that strength. Experts claimed that they were able to enter into a level of consciousness called berserkergang. It is a state wherein a human body would secrete hormones that would help him in coping up with the strength such as adrenalines, endorphins and dopamine. It is not clear though if the wolf skin were able to magnify their ability that they were indeed possessing the abilities of the wolf.
The wolf-warrior was suppressed by the followers of Christianity as a form to stop paganism and other type of religions. Due to the efforts made by those people, the wolf-warrior was removed from the history and took them out from the pages of folklores and tales. Cannibalism and human sacrifice was imposed with a higher punishment by the Roman Empires thus the people practicing it retreated into the mountains.