ber·serk
 /bɚˈsɚk, bɚˈzɚk/  adj  
  : crazy and violent especially because of anger
   berserk behavior
  go berserk
   1 : to become very angry, crazy, and violent
    A worker went berserk and killed his boss.
   2 : to become very excited
    The crowd was going berserk. [=going wild]