The Saga of King Hrolf Kraki is a Scandinavian legendary tale about pre-Viking Age kings and their rivals. Also known as Hrolf's Saga, it tells of King Hrolf, a warrior chieftain who ruled in Denmark about the sixth century CE. The saga draws on a long oral tradition as it describes Hrolf's often treacherous family and recounts the exploits of his famous champions, the Berserkers.
Prominent in the saga are the Berserkers, who were said to have been members of cults connected with Odin in his capacity as god of warriors. The Ynglinga Saga describes Odin's warriors in this way:
"His men went to battle without armor and acted like mad dogs or wolves. They bit into their shields and were as strong as bears or bulls. They killed men, but neither fire nor iron harmed them. This madness is called berserker-fury."
In Hrolf's Saga, the Berserkers often appear as the core of the king's war band. They reminiscent of the warriors surrounding Odin and may have been derived from ancient bear cults.
The term Berserker could mean "bare shirt" or naked, since berserkers, as a mark of their ferocity and invincibility, are said to have fought without armor. The term may also mean "bear-shirt," reflective of the shape and nature of the bear, with which the warriors associated themselves. More literally, it may refer to protective bearskins that the warriors may have worn into battle. When the "berserker rage" was upon him, a berserker was thought of as a sort of "were-bear," a part man, part beast.
Berserkers were said to be the first sent ashore during a Viking raid. They drank a strange brew and worked themselves into such a frenzy that they jumped into the small boats, rushed ashore, and ran through the villages attacking and killing villagers before the Viking warriors came ashore. Sometimes they were so berserk that, when they jumped into the boats, some missed the boats and were drowned.
Berserkers are found today in bars, clubs, and ball games. They drink alcohol to excess, they run around without their shirts, and sometimes they paint themselves in their team colors. They may dress as Vikings or Bears. They yell, work themselves into a frenzy, and start feeling invincible. Then they run out of the bars or games attacking anyone in their way. If you encounter one of these people who have “gone berserk”, it may be a just humorous encounter or you may have to fight for your life, so be prepared.