Officially announced by Peter Jackson on his facebook page, Azog is described simply as an Orc. [Click here] Peter Jackson will be referring to the ‘goblins’ in book The Hobbit as ‘Orcs’ in the film.
King of the Orcs of Moria, Azog is described in Appendix A of Lord of the Rings as “a great Orc with a huge iron-clad head, and yet agile and strong”.
Azog’s murder of Thror in the year Third Age 2790, the subsequent defilement of the body and his scornful words to the dwarf’s servant, Nar, sparked the brutal Dwarf-Orc wars that raged the length of the Misty Mountains for six bloody years.
The revenge of Durin’s Folk was completed in the Battle of Azanulbizar (or Nanduhirion in Sindarin) in TA2799 when the forces of Azog were finally brought to bay in the valley before the east gates of Moria — a battle of which the memory still makes Orcs shudder and Dwarves weep.
Thrain II lost an eye, while Thorin gained the name “Oakenshield” when he took up a branch of oak as a defence after his shield was shattered. But it was a young Dain Ironfoot who took vengeance upon Azog, slaying him before the very doors of Moria itself.
Azog’s head was then set on a stake with a small punch of money thrust into its mouth.
Azog’s son Bolg was the commander of the Goblin forces many years later at the Battle of the Five Armies.
‘If beggars will not wait at the door, but sneak in to try thieving, that is what we do to them. If any of your people poke their foul beards in here again, they will fare the same. Go and tell them so! But if his family wish to know who is now king here, the name is written on his face. I wrote it! I killed him! I am the master! ‘
Then Nar turned the head and saw branded on the brow in Dwarf-runes so that he could read it the name AZOG. That name was branded in his heart and in the hearts of all the Dwarves afterwards. Source: The Lord of the Rings: Appendix A