Yáru (Q."gloom, blight") was a Spirit of the Shadowfolk and a lesser servant of Mandos.As Morgoth had been incarcerated in the Halls of Mandos, he had befriended some of Mando's lower following and lured them to spy and secretly serve him. As Morgoth escaped Aman after the destruction of the Two Trees, Yaru was among those corrupted shadow spirits who followed their master into exile. Yaru eventually found his doom as his master sent him as a herald to negotiate with the Valar Tulkas. Tulkas did not recognize Yaru as a legitimate mediator and executed Yaru by throwing him down from a high mountain of Araman.
Items[]
It is quite possible that Yaru bore some of the Noldorin artifacts stolen from Formenos. Yaru could have been present with Melkor and Ungoliant, or at least preyed upon the spoils of Finwe. No doubt having such items from Feanor would have increased his arrogance to the point of standing before all the Valar at once.
Note[]
Morgoth's Ambassador is mentioned briefly in the Book of Lost Tales, but he remains unnamed.