Know your orc: A ranger's field guide to orcs
Black Uruks were an extremely rare breed of Orc, being one of the most high-ranking and were powerful. They were considered elite, being the best of Sauron's army, and two were notable of being Black Uruks: Murgash, lieutenant of Gothmog, and Shagrat, captain of Cirith Ungol.
They were the largest orcs that Sauron ever birthed, they all served him directly. Many of them were killed such as Murgash and thousands of others. In a LOTR deleted scene, an army of them were wearing Uruk hai helm's deep armor and marching through Gorgoroth.
The Ettenmoorian orcs came from Gundabad, but built a kingdom in the Ettenmoors, based at Mount Gram. Their leaders were Gorkil the Goblin King, Golfimbul and Tharzog.
Goblin-men were a people or race of creatures that were bred by Saruman, apparently by blending the races of Orcs and Men. They were similar with the Half-orcs, at least in their resistance to the sunlight, an attribute that differentiated them from the full Orcs. The Squint-eyed Southerner was possibly a Goblin-man, as Frodo Baggins commented that he looked "more than half like a Goblin." Goblin-men fought alongside Half-orcs, Hill-men and Dunlendings in the Battle of the Hornburg.
Guldur Orcs are a group of orcs who settled in the ancient fortress of Dol Guldur in approximately TA 2941, none of them was from the abandoned fortress, but were from Moria which mainly from Mount Gundabad.
The Gundabad Orcs were the Orcs inhabiting Mount Gundabad. They had attacked the mountain and took it from the Dwarves of Durin dwelling there. They were the servants of the Witch-king of Angmar before they had seized Gundabad.
In Peter Jackson's The Lord of the Rings film trilogy, the Gundabad Orcs had appearance similar to that of the Orcs of Mordor, the footsoldiers of the Dark Lord Sauron. They had dark skin, fangs, claws, and a small amount of hair. They wore armor of brown and white fur coats threaded with various beast's teeth and Wooden shields bearing the Eye of Sauron. They, like many orcs, used long sharp swords called Scimitars with which they impaled and slashed their victims.
Half-orcs were among the Dunlendings who came to Saruman's banner of the White Hand in Isengard. Many were counted among the strongest servants of Saruman. The half-orcs mostly perished at Battle of the Hornburg, either before the fortress walls or by the Huorns.
Hobgoblins were stronger, larger, and more menacing than other orcs. They are mentioned only once, by Gandalf, in The Hobbit. He described them as one of the many kinds of orcs inhabiting the Wilderland. Many of them are probably some form of Uruk-hai or else a particularly large breed of orcs living in the wilderland. There is however no specific orc-race called hobgoblins but it is simply the name for all larger kinds of orcs, used in The Hobbit.
J.R.R. Tolkien wrote in a 1971 letter that in folklore hobgoblins were actually particularly small goblins of the traditional (not the Tolkien) kind, which is opposite of the case with the "goblins" (orcs) of The Hobbit.
They were slaves, messengers, and warg riders placed in the service of Isengard during the War of the Ring. They helped breed the Uruk-hai and crafted their weaponry.
Morgul Orcs, more commonly known as the "Orcs of Minas Morgul", were some of the bravest but lesser Orcs in all of Mordor, originating directly in Minas Morgul.
The Morgul Orcs were the inhabitants of Minas Morgul, the lair of the Nazgûl. They fought in almost all the major battles in the War of the Ring. It is most likely that these orcs were a cross between Goblins and Snagae.
The orc berserkers are the most ruthless and fearsome orcs from Mount Gundabad, and struggle with admirable fervor. During the Battle of Five Armies, Bolg leads a hundred of these orcs as the vanguard of his massive army.
Orcs of Mordor
Orcs of the Misty Mountains
A Snaga was/were the lowest or lesser breed of orc. They were used as slaves, warg riders, messengers, and were lower in ranking and size than Uruks, Morannon orcs, Orcs of Minas Morgul, and other larger ones in Mordor.
Tolkien described the Uruk-hai of Isengard as large, smart orcs with slanted eyes, thick legs, and large hands. They were armed with bows made of yew and short, broad-bladed swords. The Isengarders' equipment was noted as quite different from normal orcish gear (such as that used by the Uruks of Mordor).
They were faster than normal Orcs and could travel during the day without being weakened. They were not only faster but smarter, stronger and larger, though they were still shorter than Men.
The Orcs and Uruks in the service of Barad-dûr, the folk of Mordor, used the symbol of the Red Eye of Sauron. The Red Eye was also painted on their shields. At least one, a guard on the march with Merry and Pippin, had a black knife with a long saw-edged blade, used by Pippin to cut through the ropes on his hands. They were all long-armed and crook-legged, not as tall as the Isengarder Uruks but larger than the Moria Orcs. They could see better in the dark than the Isengarders could.
The Uruk-hai of Saruman the White used an S elf-rune wrought in white metal on the front of their iron helms. It was clear this "S" stood for Saruman, because their shields had a small white hand (the symbol of Saruman) centered on a black field. Aragorn commented that their gear was not in the manner of other Orcs at all. Instead of curved scimitars, they used short, broad-bladed swords. Their great bows were made of yew wood, in length and shape as those of Men. They also appeared different physically: greater stature, swarthy, slant-eyed, thick legs and large hands. Although they did not like the light of the Sun, they could withstand it better than other orcs. Saruman promised them man-flesh as a treat.