The Witch-King of Angmar is a hooded wraith with an assortment of cutlery decorating his head. He is king of a race of beings called Nazgul, wraiths that have no form at all so they have to wear robes to give them form. Unfortunatly for them, their master Sauron gives them robes that are at least a week out of fashion. This makes them embarrased to be out in ublic which explains why they only travel at night.
The Witch King used to looks like all the other Nazgul, but after one of their missions ended in disaster (with the Witch-King accidently stabbing an innocent bystander and his babysitter coming along and washing them away with a river) the Nazgul were given an upgrade. Instead of riding horses they got giant winged lizards to fly, and the Witch King got some awesome armour made up of bits of tin-foil and broken cutlery that the orcs found at Saruman house after he died.
The Witch-King then went on to lead the charge of the orcs against the white city of Gondor, ruled by men, because of their obvious racism. The Witch-King is all for equal rites so he attacks the city. However, another obviously racist bastard came along to stop him - Gandalf the White. After a short battle the Witch-King had Gandalf right where he wanted him when suddenly more Humans arrived - this time with their King, Theoden.
The Witch-King swooped down and attacked the King, knocking him off his horse and grieviously wounding him. Just as the Witch-King was about to strike, some stupid midget stabbed him in the leg with a letter-opener. If that weren't enough, some woman stabbed him in the face with a magic sword and crushed his tin-foil helmet. After this, the Witch-King crawled away in disgust, and the orc army fled the battle.
After this, the Witch-King went to live with his grandmother, Darth Vader. Things went alright at first but their differences in opinion soon led to a squabble between them, during which Radagast used his TARDIS to travel forward in time to this point and steal the Witch-King's sword. Poor him.