Netherstrand Longbow

Source
Used during the fight with Kael'thas Sunstrider in Tempest Keep.

The bow has a "Use:" property on it which will put a in your bag. This can then be looted to get six stacks of arrows. The bow and its arrows are conjured items that will disappear after 15 minutes, when the fight ends, or when exiting Tempest Keep, whichever occurs first.