The Eye of Angor Rot is a powerful magical object as well as one of the body parts of the sorcerer and assassin, Angor Rot.
The Eye of Angor Rot is a spherical stone that lets Angor see, even when it is not connected to his body. The Eye starts off as orange-yellow, but once Angor's soul is destroyed, it becomes greyish-white.
Angor Rot's Eye
After being tasked by Stricklander to kill the Trollhunter, Angor Rot used the Eye to spy on Jim Lake Jr., slipping it into his bookbag as he entered Trollmarket. In the Trollmarket library, Angor watched as Jim and his team planned to go to Gatto's Keep to obtain one of Gatto's treasures. Although Angor was unable to see what the group were trying to find, he told Stricklander that it was unlikely that the group would return.
The Eye is separated once again to spy on Jim, Strickler, and Draal's preparations for Angor's inevitable assault. Draal notices the Eye after polishing his axe, and after he and Strickler fail to capture it, Jim traps it in a jar. Angor learns of the secret tunnel that Draal built into Jim's basement, and uses it to circumvent Jim's defenses. Using his other eye, Angor creates a blackout in the house, causing chaos and managing to wound Strickler and Barbara Lake while trapping Draal and escaping.
Faced with the conundrum of battling Angor without the Sword of Daylight, Strickler tells Jim that the Eye contains a gemstone that can counter Angor's magic. With Strickler's guidance, Jim cuts the Eye and places the stone inside into his amulet. When Angor invades Trollmarket, Jim is able to reclaim his sword and battle Angor. It is currently unknown whether the stone is still within the amulet.