Thas'dorah, Legacy of the Windrunners, or simply Thas'dorah, is the marksmanship hunter artifact weapon in Legion.
Thas'dorah was the bow of Alleria Windrunner, retrieved from the Sunwell, said to "radiate power." In Thalassian, Thas'dorah translated to "Valor of the Forest." Alleria would have taken Thas'dorah with her to Draenor during the Second War, and it disappeared with her when the Dark Portal closed, trapping the Draenor Expedition on the other side. Later, during the Burning Legion's third invasion of Azeroth, Thas'dorah was found by Vereesa Windrunner and the Master Hunter of the Unseen Path on the Legion world Niskara, with Alleria no where to be seen. Thas'dorah was taken by the Master Hunter.