Mansun

The fact that Gollum had a much increased lifespan also points to the likelihood of an undead wraith developing. If Gollum did not perish at Mount Doom, would it have been possible for him to return to his former self phsically or mentally? Almost certainly not, as the Ring & he were like one, much like the Ringwraiths were with their rings. When the Ring was destroyed, Gollum would die as the Ring has become his only reason for a will to live.

I believe Aragorn referred Gollum as a slimy thing in the Council of Elrond, & slime is normally green/brown??