Black Arrow

An arrow roughly 2 meters in length with heavy twisted steel heads, combining elements of both spears and harpoons. It's the only know weapon capable of piercing the armoured hide of dragons. It was created by the Dwarves of Erebor, a family heirloom passed down from the Lords of Dale. Bard the Bowman eventually used it to kill the red dragon Smaug during the defense of Esgaroth.