Full name: Sméagol
History:Sméagol was one of the Stoors, a race of hobbits that, unlike most of their kind, lived near rivers and knew something of boating, swimming, and fishing. One day, when Sméagol and his cousin, Déagol, were fishing, Déagol fell into the river, and found, buried in the mud, the One Ring. Sméagol immediately wanted the Ring, claiming that Déagol should give it to him as a birthday present. Déagol refused, and his treacherous cousin murdered him. Sméagol used the Ring's power of making the wearer invisible to find out secrets and spy on his kin. The Stoors grew to distrust him, and called him "Gollum" because of the gurgling noise he made in his throat. Sméagol grew to hate all light, both sun and moon, and leaving his kinsfolk, went off to live in the caves under the mountains. He lived there for nearly 500 years, constantly talking to the Ring and calling it his "precious."
In TA 2941, Bilbo Baggins, who was lost in the caves, chanced upon the Ring, which Gollum had accidentally dropped a few days ago. Bilbo and Gollum met, Bilbo foolishly introduced himself, and the two played a riddle-game: if Bilbo won, Gollum would show the way out of the caves; if Gollum won, he would eat Bilbo. Bilbo won the game with the questionable riddle "What have I got in my pocket?" The answer was "a ring," but Gollum of course didn't guess correctly--his three guesses were "Handses," "Knife", and "String or nothing" (the last being two guesses combined into one, although both were incorrect). He paddled to the island where he lived, thinking to put on the Ring and sneak up on Bilbo unawares, but the Ring was gone. Now Gollum began to suspect what was really in Bilbo's pocket, and ran after the terrified hobbit. Bilbo put on the Ring accidentally, and Gollum ran past the invisible "thief."
Afterwards, Gollum vowed to find the cursed Baggins who had stolen his precious. Gollum searched long for Bilbo, but failed to find him and wandered to Mordor. There he was tortured until the orcs got two words from him: "Shire" and "Baggins." Gollum escaped (or was let loose) from Mordor in TA 3017. Aragorn caught him, and brought him to Gandalf, who, after learning Gollum's story of the Ring and the Baggins, entrusted him to the Wood-elves of Mirkwood. The Elves guarded Gollum as carefully as they could, but they couldn't bear to keep him in prison, and let him climb trees in the forest. One day Gollum refused to come down from his perch, and around June 20th, TA 3018, he was rescued by orcs.
Gollum continued to hunt for Bilbo, and followed the Fellowship of the Ring from Moria to the Great River. Frodo and Sam finally caught him in the Emyn Muil, and forced him to lead them through the Dead Marshes. Gollum did so faithfully, and even led them to the Black Gate of Mordor. When Frodo decided there was no possible way into Mordor through the Gate, Gollum led them to Cirith Ungol, saying that it was a secret and unguarded path. On the way the hobbits were captured by Faramir, but Frodo begged Faramir to spare Gollum's life, though Faramir distrusted the creature and saw the potential for terrible treachery in him. Gollum continued to lead the hobbits, and after guiding them up many stairs, finally betrayed them to his friend, Shelob. Gollum tried to kill Sam, the "nassty hobbit," but Sam fought him off.
Gollum continued to follow Sam and Frodo through Mordor, and at the very fires of Mount Doom, bit off Frodo's finger that had the Ring on it. Gollum stepped too close to the Crack of Doom in his gleeful dancing, lost his footing, and toppled in, destroying the Ring and himself.