Visit an undead barbarian in An Empty Tavern (27348), he will speak sayto him yes, he will speak some more, then nod at him.
He will give you a location and mob name to kill, recover a body part from requested mob and return it quickly to the barbarian.
If you forget your target, repeating the above will yield the same mob as output. Target mob is reset on reboot, no other known method.
For valiantly assisting a fellow warrior in his need, the Powers have granted thee a Mark. You have been granted the Mark of Barbarity! You gain 35 practices!