what kind of creature is gollum from the lord of the rings?

The stories we know and love of Middle-earth are predominantly set in the Third Age, by which time the hobbits have found a peaceful existence within Eriador, home of the Shire and Bree.

The answers to the question surrounding the lineage of these peace-loving beings, can be found by delving into the prologue of Tolkien’s The Lord of the Rings books, ‘Concerning Hobbits, and other matters.’ Here Tolkien introduces the origin of the creatures, dating right back to the etymology of the Halflings (so-called because they are on average half the size of the race of Men in stature).

During Peter Jackson’s 2001 film adaptation of The Fellowship of the Ring, at Bilbo Baggins’s long-awaited 111th birthday party, he gives a speech to the many hobbits in attendance: Bagginses and Boffins, Tooks and Brandybucks, Grubs, Chubs, Hornblowers, Bulgers, Greyskulls, Bracegurdles and Proudfoots (or Proudfeet!) But where did these illustrious families come from, and how did they end up in The Shire?

What kind of creature is gollum from the lord of the rings?