Name: Kel'Thuzad
Nickname: The Archlich, Lich Lord of the Plaguelands, Lord of Naxxramas
Age: 30s (In human form) ??? ( Lich form)
Gender: Was once male 
Abilities: Before becoming a lich, Kel’Thuzad had great skill in dark, death, and necromantic magic. After becoming a lich, he still retained most of these powers, only on an even more powerful scale, as well as the ice based magic common for liches.
Species: Lich
Appearance(s): [IMG]http://i.imgur.com/pUxKk7Q.jpg[/IMG]
From: Warcraft 
Other: A Lich can be killed if you destroy the thing they have put a peice of their soul onto if that thing isnt destroyed he will just come back to life