SRD:Berserking Sword

Sword, Berserking: This item appears to have the characteristics of a ''+2 greatsword. ''However, whenever the sword is used in battle, its wielder goes berserk (gaining all the benefits and drawbacks of the barbarian’s rage ability). He attacks the nearest creature and continues to fight until unconscious or dead or until no living thing remains within 30 feet. Although many see this sword as a cursed object, others see it as a boon.

Moderate evocation; CL 8th; Craft Magical Arms and Armor, rage, bestow curse; Price 17,500 gp.