Gollum

Smeagol was a hobbit like creature who came into possession of the Ring of power after murdering his cousin, Deagol. Smeagol became shunned by his own kind and fell under the influence of the Ring. As Gollum he hid in the Misty Mountains where he eventually encountered Bilbo Baggins, who ended up taking the Ring from him during a riddle game. Gollum finds Frodo with the Ring, and agrees to show him the way to Mt Doom. Samwise Gamgee gives Gollum/Smeagol the dual names Slinker and Stinker during their quest.