Shelob, J. R. R. Tolkien’s show-stopping monster from The Lord of the Rings: The Two Towers novel, has turned generations of readers into arachnophobes. The giant spider dwelt at the top of the stairs to Cirith Ungol and devoured all who crossed her path. Peter Jackson brought her to life in his movie adaptation of The Lord of the Rings, but for pacing purposes, he moved the encounter to The Return of the King. Regardless, Jackson reminded a whole new generation why giant spiders are terrifying. Except, Shelob might not be a spider at all.
She indeed possesses a spider-like form, with the ability to spin webs to capture prey and paralyze them so she can feed on them slowly. But beneath those surface trappings, she’s closer to the Balrog than she is to any of the more mundane monsters of Middle-earth, and her origins go back to the First Age.
According to Tolkien, Shelob was the child of Ungoliant, a spirit of darkness who took the form of a giant spider and allied herself with the dark spirit Melkor in his conflict against the elves. Her origins were uncertain, but she hated the light and fed upon it, making her a natural partner for Melkor. Their partnership eventually dissolved, and Ungoliant fled before Melkor’s Balrogs. In the wilderness, she bred with giant spiders. Shelob was one of her offspring.
Tolkien made spiders a common villain in his stories, most notably in The Hobbit, and most of them were considered “the children of Ungoliant.” The spiders of Mirkwood are a strong example, though they were presumably many times removed from their progenitor. The link explained things such as their ability to speak to each other and their hatred of the light. Shelob, however, was her direct child and demonstrably more powerful than they. She was also the last of Ungoliant’s children to survive to the War of the Ring.
Ungoliant was a foul spirit. As her spawn, Shelob inherited many of those traits, making her something akin to a demon in living form. The Two Towers specifies that she predates Sauron’s arrival in Mordor, creating her current lair hundreds of years earlier. Sauron allowed her to stay because she made an excellent guard for the stairs at Cirith Ungol, but “she served none but herself,” as Tolkien put it, and she devoured Sauron’s orcs as readily as elves and men.
Shelob’s cunning and longevity speak to her mother’s blood, but it’s her battle with Sam that truly reveals she is more than mere flesh and blood. According to the text, light from the Phial of Galadriel fills her with fear as Sam wields it and “infects” the wounds he had already caused with the elf blade Sting. Furthermore, the Ring grants him enhanced hearing, allowing him to perceive Shelob’s “bubbling misery.” That may merely be an incidental effect of the Ring, but it echoes back to the language of the Mirkwood spiders and suggests a strong connection between the two. In any case, appearances are clearly deceiving. As spider-like as Shelob looks, her dark origins took elf magic to stop.