The subject of this article or section originates from non-canonical sources. To find out about what is considered "canon" see LOTR:Canon.
Goblin Mercenaries were Goblins from Goblin-town that joined the forces of Gundabad and Misty Mountains to avenge the Great Goblin's death or to get their hands on the reward for aiding the Dark Lord Sauron.
In TA 2941, after the death of the Great Goblin, as many as 200-400 Goblin Mercenaries from Goblin-town chose to avenge their king or were eager to get their hands on the reward so they joined Azog's army to lay siege on the Lonely Mountain. During the Battle of Five Armies, several dozen Goblin Mercenaries activated catapults mounted on the backs of several Great Guldur War Trolls (who possibly came from somewhere near these orcs) to destroy the walls of Dale, while more than a hundred others stormed into the city with the Guldur Orcs, Trolls, and Ogres. Another group of about a hundred Goblin Mercenaries arrived first at Ravenhill to attack
Thorin II Oakenshield and Dwalin while Fíli and Kíli entered the caves of Ravenhill to search for Azog. The Goblin Mercenaries were easily defeated by Thorin and Dwalin. The last remnants of the Goblin Mercenaries band was killed by the Great Eagles, led by Gwaihir the Windlord.