Berserker rage

Live past death.

 \       
  \    O                      
  _\|  |  }       , _          \O_
    M_/|\_|}    O/ /    __\    /
       |  }     /\|/\_    /  _/\
      / \      ,,,,,,,      '   \
    _/   \_                      '

Berserker rage allows the barbarian to perform certain actions (such as quaffing potions) with negative hitpoints.