A creation of the Necromancer, Goblok was part troll and part orc, made as a twisted experiment to intermingle the two races. Devoted to his master, he led parties of Kazgumhoth to search for the One Ring in the river Anduin, attempts discovered soon by the Wizard Saruman.
Goblok's search for the Ring proved futile, making the Necromancer realize that either it had been washed away into the Great Sea or that it had ensnared a new bearer. Fearing he had brought unwanted attention, Goblok was recalled to Dol Guldur and hid in the fortress' depths until the White Council's eventual confrontation with the Necromancer.
Sometime later, Goblok and his Orc party were tasked with capturing the creature Gollum, who had knowledge on the possible whereabouts of the One Ring. The group attacked the Elves holding him captive, but were unable to pursue him and so, Goblok sent two scouts ahead to lead the way. After the Orc duo was found dead, Goblok had his party separate to cover more ground and followed a trail which led them to the Ranger Aragorn.
Challenging him to combat, the huge Orc chieftain tried to overpower the Ranger with his brute strength. After a short brawl, Aragorn was able to bring Goblok down and stab him mortally in the throat, ending him.