Gollum is a great character because of the fiction he derives from and the fact that his traits work well within the confines of Don't Starve's mechanics. He comes with the One Ring in his inventory and if you equip it, he can turn invisible. This is awesome for escaping enemies or stealing items out from under their noses. The ability is supplemented by his added speed, so it's very apparent that Gollum is not much of a fighter.
In terms of scavenging, Gollum doesn't need a pole to catch fish, as he is more than adept at using his hands. Fish give Gollum a higher boost to hunger and sanity than any other character, but if he eats fruits or vegetables, he will become disgusted and lose sanity. So remember, the best way to survive with Gollum is to run and catch those fish...so juicy sweet.
To download the Gollum mod, head over here.