Headhunter's Trophy

The Headhunter's Trophy is an exclusive item obtainable by completing the "Headhunter" achievement. The achievement requires completing 5 bounty quests.

So far, it appears to be that a player can only obtain this item once (when the quest is completed).

If you combine the Headhunter's Trophy with a weapon, it will get the "Headhunting" modifier. The name explains it all: It allows the wielder to collect heads from their fallen enemies.

The Headhunter's Trophy can not be added to weapons with any sort of "bane" modifier.