Gollum
Gollum is a fictional character from J. R. R. Tolkien's legendarium. He was introduced in the 1937 fantasy novel "The Hobbit", and became an important character in its sequel, "The Lord of the Rings". Gollum was a Stoor Hobbit of the River-folk, who lived near the Gladden Fields. Originally known as Sméagol, he was corrupted by the One Ring and later named Gollum after his habit of making "a horrible swallowing noise in his throat".
The Lord of the Rings: The Third Age
Meanwhile, during the Third Age, a still weakened Sauron covertly established a stronghold at Dol Guldur. In response to this undetermined evil, the Valar sent five Maiar to Middle-earth. Taking the form of wizards, they were led by Saruman. Unsure of the origin of the evil power in Dol Guldur, the wizard Gandalf was sent to investigate. However, Sauron hid from Gandalf, waiting for four hundred years before returning. Around the same time, the One Ring was found by a Hobbit named Sméagol, who became utterly corrupted by it, living in the caves of the Misty Mountains, and physically transforming into a creature known as Gollum. For five hundred years, Gollum was consumed and corrupted by the Ring. Eventually, Gandalf was able to determine the evil presence in Dol Guldur was indeed Sauron. Gandalf reported back to the White Council, but Saruman dissuaded them from moving against Sauron. Only when he learned the One Ring may be in the vicinity of the Gladden Fields did Saruman agree to attack Sauron, hoping to find the Ring himself. The Council drove Sauron from Dol Guldur, unaware that he knew the Ring had been found. Just prior to Sauron's departure, the Ring passed to another hobbit, Bilbo Baggins, who used it to assist in the victory of elves, men and dwarves at the Battle of the Five Armies. Sixty years later, Gollum was captured by orcs, and taken to Mordor, where he was tortured into revealing the owner and location of the Ring; Bilbo Baggins of the Shire. In the meantime, Bilbo had left the Shire to live in Rivendell, and upon the advice of Gandalf had (very reluctantly) given the Ring to his nephew, Frodo Baggins. With the information given him by Gollum, Sauron, still unable to take physical form, thus sent the Nazgûl to the Shire to retrieve the One Ring. Frodo, and his friends, Samwise Gamgee, Peregrin "Pippin" Took and Meriadoc "Merry" Brandybuck managed to escape the Shire and make it to Bree, where they encountered the ranger Aragorn, the last surviving descendent of Isildur, and rightful heir to the throne of Gondor. Aragorn protected the hobbits on their journey to Rivendell, and upon their arrival, Elrond formed a Fellowship with the goal of bringing the Ring to Mordor to destroy it. The Fellowship is composed of Frodo, Sam, Merry, Pippin, Aragorn, Gandalf, a silvan elf from Mirkwood named Legolas, a dwarf from Erebor named Gimli, and a man from Gondor named Boromir, son of Denethor, Steward of Gondor.