The Great Goblin was an Orc leader in the Misty Mountains. The Great Goblin was a very large Orc with a huge head. He was the chief of a group of Goblins who lived in Goblin-town near the High Pass. They preyed on travelers who used another, easier pass near the main gate of Goblin-town until people started avoiding that route over the mountains. The Goblins then made another gate that opened into a cave that they called the Front Porch at the top of the High Pass.
In the summer of 2941, the Dwarves of Thorin and Company along with Bilbo Baggins were captured on the Front Porch and were brought before the Great Goblin in his great cave. He was seated on a flat stone and surrounded by armed guards. The Great Goblin demanded to know what the Dwarves were doing in the mountains.
When it was revealed that Thorin carried the Elvish sword Orcrist – which the Orcs feared and called Biter – the Great Goblin was enraged and leaped to attack Thorin. Then Gandalf appeared and killed the Great Goblin by running him through with his sword Glamdring, called Beater by the goblins.
The death of the Great Goblin angered the Goblins of the Misty Mountains. A great army of Goblins and Wargs was amassed by Bolg – whose father Azog had been killed by a dwarf Dáin II Ironfoot. Bolg’s forces tracked Thorin & Company to the Lonely Mountain where they fought the Battle of the Five Armies against the Dwarves, Elves, and Lakemen.