Zerlúk was an Uruk-Hai soldier who was born in the underground caverns of Isengard. During the War of the Ring, Zerlúk spent most of his training to prepare for war against the west and served in Uglúk's company to go on the hunt for The Fellowship of the Ring. Under Uglúk's orders, he was to search and capture halflings that carried a great value to Saruman and were to be brought back to Isengard alive, unspoiled, and unsearched. Zerlúk never asked questions and followed Uglúk's orders. When he saw two of the halflings that he was meant to capture, Zerlúk and his fellow scouts were this close in capturing them until they were ambushed by Boromir. Zerlúk doubled back on him, but the Gondorian wounded him.