Difference of the Goblins and orcs in the Legendarium
Orcs and the goblins were synonyms in the Lengendarium so there isn’t a distinctive defined difference in the original scripts of the stories of the Legendarium.
However, goblins were mostly referred to as the orcs of the Misty Mountains and they were described as a bit inferior compared to the orcs of Morodor.
In The Hobbit, the term goblin was used more to describe the orcs while in the Lord of the Rings, orcs became a more common term. J.R.R Tolkien first published The Hobbit before the Lord of the Rings, in 1937 while the Lord of the Ring series were published in 1954 and 1955.
J.R.R. Tolkien may have introduced goblins first because it was a more common term so the public could understand the nature of orcs easier when The Hobbit was published.
In all the movies of The Hobbit and Lord of the Rings, orcs and goblins were described as vicious creatures that could rival the strength equally with dwarves, humans and elves.
However, in the novels, orcs and goblins were definitely smaller, weaker than the humans, elves and dwarves.
As J.R.R. Tolkien first introduced the fantasy concept of an orc, over the time the public perception of an orc changed to a masculine strong and terrifying creature so the movie series would have introduced orcs as strong as the dwarves, humans and elves.
Giants
There aren’t many descriptions of giants by J.R.R. Tolkien nor Christopher Tolkien, while Thorin and Company with Gandalf and Bilbo Baggins met giants that were throwing rocks at each other during a storm.
Giants were mentioned in the early drafts of the Silmarilion and The Hobbit and Lord of the Rings but most of them were removed from the actual publications. In The Hobbit An Unexpected Journey, there are depictions of the giants during Thorin’s party climbing up the Misty Mountains.
Goblin Town
Azog was the chief of the Orcs of Moria while the Great Goblin was the chieftain of Goblin-Town. The goblins (goblins = orcs) of the Misty Mountains would dig numerous tunnels and underground colonies beneath the Misty Mountains.
The numerous tunnels and caves linked up together would form Goblin Town where the orcs/goblins of the Misty Mountains would dwell.
Great Goblin
Azog was also called the Great Goblin in the novel while the movie strictly distinguished the Great Goblin and Azog. In the novel, at this time point Azog was already dead and Azog was described as the leader of the orcs of the Misty Mountains, especially Moria.
In the novel, it might be that Bolg absorbed remnants of Azog’s forces of the Misty Mountains orcs in Gundabad while the Great Goblin absorbed the rest and took over the Misty Mountains.
The Great Goblin was an unusually huge orc/goblin that led Goblin Town who recognized Thorin Oakenshield’s sword Orcrist and cried to quickly slay them as the Great Goblin was aware of the notorious Orcrist among the goblins as the goblin slayer.
Gandalf would slay the Great Goblin with the Foe-hammer Glamdring.
Cause of the Battle of Five Armies – Death of Great Goblin
In the movie, Azog would assemble the orcs of Gundabad, Moria and the Misty Mountains and the goblins by the order of Sauron.
However, in the novel, Azog was already dead and the death of the Great Goblin was one of the main causes of the orc’s march to Erebor.
Azog’s son Bolg of Gundabad was eager to take revenge on the dwarves and after the death of the Great Goblins, the orcs/goblins of the Misty Mountains would ally with Bolg of Gundabad to attack the dwarves at Erebor.
After Bolg received news of the death of Smaug, the orcs/goblins already eager to avenge the Great Goblin and Azog would march to Erebor without hesitation.
Smeagol / Gollum
After murdering his cousin Deagol and being banished from his village at the vales of Anduin because of the obsession with the One ring, Smeagol or Gollum lived in the caves of the Misty Mountains for 400 years. Smeagol lived off fish from the small lake in the caves of the Misty Mountains and even cannibalized on passing by goblins.
The One Ring would prevent Smeagol from disintegrating and gave an evil influence so Smeagol would have two personalities. To simplify Smeagol’s identity, Smeagol was kind and Gollum was evil.
Gollum and Bilbo Baggin’s Riddle Game
Bilbo Baggins would pick up the One Ring when he fell near the nest of Gollum and Smeagol. Gollum wanted to eat Bilbo Baggins so Gollum would suggest a riddle game to Bilbo Baggins while the prize would be letting Bilbo Baggins know of the way out of the cave.
Gollum’s plot was to cannibalize on Bilbo Baggins anyways, however Gollum was caught by surprise as Bilbo Baggins was just wondering what the One Ring was in his pocket while Gollum accidentally thought Bilbo Baggin’s self-talk “What is in my pocket?” was a riddle.
Gollum, after he lost the Riddle Game tried to put on the One Ring to conceal himself and cannibalize Bilbo Baggins anyways but then he discovers that the One Ring was missing and Bilbo Baggins took it.
The One Ring, second ring bearer Bilbo Baggins
Bilbo Baggins would later tell the story of Gollum to Gandalf while he hid the fact that he obtained a golden ring that was actually the One Ring that Gandalf feared.
After learning Bilbo Baggins had the One Ring around the timepoint of Lord of the Rings Fellowship of the Ring, Gandalf would explain that the One Ring had its own will to return to Sauron and decided to leave Gollum in the possession of Bilbo Baggins.
Later on, Gollum would search for Bilbo Baggins and the Shire but ended up in Mordor captured by Sauron. Gandalf would also search for Gollum to confirm the presence of the One Ring by the Hunt for Gollum.
Eagles
The eagles were the birds that served the Lord of the Valars Manwe and during the First Age, the Great eagle Throndor was the king of the eagles.
During the third age, the Eagles would nest in the north part of the Misty Mountains and they were led by the Great Eagle whose name is unknown and later on during the War of the Rings, the eagle Gwahir led the eagles.
The eagles were especially close friends and allies with the Brown wizard Radagast and Radagast would help Thorin and Company by sending the eagles for their escape from the Misty Mountains.
The eagles would help the dwarf, human and elves at the Battle of Five armies and later during the War of the Ring, Radagast would send Gwahir to save Gandalf from Saruman when Gandalf was locked up in the top of Orthanc as well.
