Unlight

Unlight was the weapon and cloak used by Ungoliant.

It came solely from her and it was an all-encompassing darkness all its own and a thing of unspeakable horror and dread, for it muffled and swallowed all light in its path.

Usage and History
During the Years of the Trees when she lived in Avathar, Ungoliant wove a great net of Unlight around a great ravine there and it became her nest. Later, when Melkor came to Avathar and asked for her help in the destruction of the Two Trees promising her all their light, she followed him using the Unlight as a cloak and to hid themselves and their approach. After her poisoning of the trees and draining them of their light, she again used it to cover their escape and its great darkness hindered and prevented even the steadfast determination of Oromë and Tulkas.

Afterwards she used her great dark webs of Unlight to torture Melkor when he refused to surrender the Silmarils to her. Being driven off by Balrogs, she dwelled in Ered Gorgoroth, in her lust, she devoured herself and its role in her death is not clear.