Berserker

berserker, n., D&D-ism 1. in general usage, an ancient Scandinavian warrior, frenzied in battle, and believed to take on bear- or wolf-like characteristics; from berserk, Old Norse berserkr (björn "bear" + sarkr "shirt"); 12th c. 2. in Dungeons and Dragons, a character class, a subclass of fighter, with the ability to frenzy in combat.[GJ1]