Shelob is a giant, malevolent spider and a significant antagonist in "The Lord of the Rings." She dwells in the Torech Ungol, a pass in the Ephel Dúath on the western border of Mordor. Descended from Ungoliant, Shelob predates even the arrival of Sauron in Mordor. She plays a pivotal role in "The Two Towers," where she nearly kills Frodo before being driven away by Sam.