Unlike the Necromancer's Curses, Battle Cry affects 'Possessed' type monsters.
Gifted Barbarian warriors can benefit from their connection to their totem animals to exploit the primal fears of their opponents. Once a Barbarian unleashes the Battle Cry, even the legions of the dead will become so distracted that they falter in their quest for victory. This permits the warrior an easy kill.
↑Diablo II Manual, page 69. Blizzard Entertainment, 2000.