Amulet of Fury - +2 to attack, +2 to initiative, gives all units berserk (like dwarves).
Spiked Armor - +3 to defense, +1 to attack, gives all units 10% damage reflection.
Claw Boots - +3 to attack, -1 to initiative, gives all units a crippling strike.
Assembled artifact - Berserker's Garb - +10 to attack, +5 to defense, +3 to initiative, gives all of the above abilities.