What makes Gollum's Character So Effective in The Lord of the Rings Trilogy?

Gollum is what Frodo could become. Gollum was once-upon-a-time a hobbit. Gollum and is Frodo’s mirror-future reflection if Frodo lets the One Ring dominate and possess him. Gollum has become possessed by the Ring and Frodo could if he does not manage to deal with the weight of the Ring. We feel sorry for Gollum, just as Frodo feels sorry for him because Frodo knows what the weight of the One Ring can do to someone. Frodo knows the pain Gollum is facing. The need, want and desire to have the One Ring is very powerful.