Berserker

In the Old Norse written corpus, berserker were those who were said to have fought in a trance-like fury, a characteristic which later gave rise to the modern English word berserk. Berserkers are attested to in numerous Old Norse sources. This practice was also commonly thought of to be brought on or enhanced by the use of psychoactive drugs, with the most likely candidates being henbane and/or alcohol. The proposed hypothesis which states they may have used muscimol mushrooms during berserkers has largely been discredited, especially given the known psychoactive effects of muscimol.