The Lion, the Witch, and the Wardrobe
by C.S. Lewis
Fenris Ulf is a vicious, talking wolf who acts as the Chief of the Secret Police under the White Witch. Fenris has few characteristics other than brutality and bloodthirstiness. He is responsible for the arrest of Mr. Tumnus and acts as a guard at the door of the Witch's house. When Fenris attacks Susan, Peter comes to the rescue and kills the wolf.