Sauron

http://www.empireonline.com/features/which-characters-will-return-in-the-hobbit/p14

The Lord of the Rings. The Dark Lord. Gorthaur the Cruel. The Necromancer. The Black Hand. The Nameless Enemy. Sauron. He is the ultimate enemy of Middle Earth's chief servant (Enemy number one being Margoth, his spirit was cast out through the door of time after his form was killed. His will and corruption still roams Middle-Earth). He is the one who forged the One Ring of Power. He is a Maiar of the race Ainur, an immortal, one of the first created in the depths of time, corrupted by Margoth in the First Age. He is the one that the Fellowship sought to destroy. On his side were the Goblins, Orcs, some Men, giant spiders, Nazgul, trolls, and werewolves. Sauron has a long history, but a summary of him in the Hobbit and the Trilogy is as follows; he is weak but gaining power in the Mirkwood forest. Gandalf and other Wizards band together and expel him out of his forest stronghold. He flees to Mordor and starts to build a stronghold. News of the the discovery of the One Ring reaches the very creator of it, who sends out his Ringwraiths to find it. He continues to build power throughout the Trilogy, making war on middle-earth, searching always for the Ring, which if he got a hold of it would make him practically invincible, able to subject all to his will, on his evil throne forever. His fall is caused by the destruction of the One Ring. With his fall, ended the Third Age, and began the Forth Age, the Age of Man.

http://www.killermovies.com/forums/f34/t24819.html

http://www.fanpop.com/spots/sauron/images/25023545/title/sauron-photo

The pictures of Sauron are some of the best, so I gave you a few of my favorites

To read more on this guy, read The Hobbit, the The Lord of the Rings trilogy, and The Silmarillion.
Here is another picture!!!

http://lotr.wikia.com/wiki/Sauron

Gollum

                Slinker or Stinker.  These are the two nicknames that Sam gave Gollum on his and Frodo’s journey to Mount Doom. Gollum was originally called Sméagol, until he found the One Ring. Looking at him at the time when Sméagol found the Ring to the time that the Ring was found by Bilbo, you would not believe that it was the same creature.  Sméagol was originally of a race not too distant from elves or hobbits, sort of in between; however, years after he found the Ring, he looked like a mix between an emancipated hobbit and an orc or goblin. After Bilbo found the Ring and escaped with it, the long time keeper of the Ring, Gollum, found a new abiding hate for all things Baggins, “We hates Bagginses, yes we do, my preciouses…we hates them,.” This might be something that you would hear out of Gollum’s mouth; however, in The Return of the King he leads Frodo and Sam to Mordor, granted he did it for his own gain,  but he did it. In the final book, Gollum develops or shows two personalities, Slinker and Stinker, or Gollum and Sméagol, when forced to swear on the Ring that he will not betray them or kill them. In the end, it is good that Bilbo and Frodo stayed their hands at killing Gollum, for he is reason that the Ring is finally destroyed. To learn his full story, read The Hobbit and the The Lord of the Rings books.