Mr. Tumnus is a fictional character from C.S. Lewis's book series, The Chronicles of Narnia. He is a faun, which is a mythical creature that has the upper body of a human and the legs and horns of a goat. Mr. Tumnus is known for his gentle and kind nature, as well as his love for music and storytelling. In the story, Mr. Tumnus befriends Lucy Pevensie, one of the main characters, when she first enters the magical land of Narnia. He initially plans to turn her over to the White Witch, but ultimately decides to help her instead. His character represents themes of friendship, loyalty, and the struggle between good and evil.