He has a split personality. One being Smegol, his former self. The other being Gollum, a personailty created by the ring that poisioned his life for 500 years.
Smegol tries to aid Frodo and Sam untill Gollum finally betrays them and sends them to Shelob.
Gives us great lines in LOTR
Sam: "PO-TA-TOES, boil em, mash em, stick em in a stew. Oh, a few coneys and some chips, even you couldn't say no to that."
Gollum: "Oh yes we could!"
1. m. Character found in the book 'Lord of the Rings' Smeagol.
2. f. Woman obsessed by desire to get a ring on her finger to the point of self-debasement and self-loathing.
3. m. Male who guides a hobbit into the Land of Mordor and thence into the Crack of Doom.
4. mf. Sexual partner intent on slipping their finger into your precious ring.