Ungoliant

Tolkien's original writings say that Ungoliant was a primeval spirit of night, named Móru,[1] who aided Melkor in his attack upon the Two Trees of Valinor, draining them of their sap after Melkor had injured them. She also consumed the reserves of light from the wells of Varda. Afterward the light of the trees persisted only within the Silmarils of Fëanor. Ungoliant helped Melkor evade the Valar by shrouding them both in the impenetrable darkness produced by herself.

Melkor had promised Ungoliant to yield anything she wished in return for her aid, but betrayed this promise by withholding the Silmarils, and summoned the Balrogs to repel her. Ungoliant fled to the Ered Gorgoroth in Beleriand. At some point she gave birth to Giant Spiders, including the character Shelob in The Lord of the Rings. In The Silmarillion, it is stated that when she went into hiding her hunger was such that she would mate with other spiders only to devour them later, with her offspring used as food once fully grown. According to The Silmarillion, Ungoliant's unremitting hunger drove her to devour herself, although an alternative sketch of Eärendil's voyage suggests that he slew her in the south.