Who is Gollum?

Gollum is a queer, small and slimy creature that lived deep down in the dark waters of the goblin caves. He ate only fish with the occasional lonely goblin that wandered too far into the caves. Gollum can sneak around almost through the entire cave since he has the ring which allows him to become invisible. In speech he likes to use the "SS" sound after some words and likes asking riddles, mainly because it is the only game he has ever played with other funny creatures that sat in their holes. For example: "Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters." The answer is wind, but that with several others proves what a riddler he was. Gollum often will talk to his "precious" and when thinking about it he starts to call himself by his own name, "gollum, gollum, gollum." I don't know why.
Gollum got the Ring of Power when a friend of his found it in the bottom of a river. Gollum was called Smeagol at that time, when he was considered a hobbit, ages and ages ago. Smeagol killed him and got the Ring for himself. No one knows what happened, maybe he got kicked out of the community he lived in. The point is that he wandered alone for a long time. During that time, the Ring began to wear of his mind, twisting it, so he got two personalities. One personality is not really mean and he regrets the murder. The other personality is really evil, and he is obsessed with the Ring. The evil personality started calling himself "Gollum." Gollum then fled to the mountains, where he hid from the sun.
One day, a lost hobbit that was on a journey, came to Gollum's lake. The hobbit's name was called Bilbo Baggins. Gollum got curious, and went to investigate. They got in the middle of a riddle game. If Gollum lost, he would show Bilbo the way out, but if Bilbo lost, Gollum gets to eat him. At the end Bilbo won, and asked for Gollum's part of the deal. By this point Gollum was angry, and went to look for his ring to kill him, under the pretext that he was going to prepare for the journey. fortunately, the Ring was in Bilbo's power, so Gollum couldn't find it. Gollum immediately suspected that Bilbo had it, so he went to kill him. Bilbo put the Ring and Gollum lost him in the caves.