gollum

A villainous, but tragic character appearing in J. R. R. Tolkien's legendarium.
He was originally an ordinary hobbit by the name of Smeagol, but The One Ring (which he called "My Precious" after his tragic transformation) warped him into a wretched, ugly, but very long-lived creature that in the end, unwittingly, contributed to the destruction of said ring, and its master, Sauron.