In C.S. Lewis’s Narnia books, Aslan is widely understood as an allegorical representation of Jesus Christ.
Aslan is the great lion who creates and rules Narnia. He appears as a figure of authority, goodness, sacrifice, judgment, and restoration. In The Lion, the Witch and the Wardrobe, he gives his life to save Edmund and returns to life, a sequence that closely parallels central Christian themes.
Lewis himself resisted treating the Narnia stories as a simple one-to-one code in which every character stood for one fixed idea. He described Aslan as an imaginative answer to the question of how Christ might appear in another world. This is why Aslan functions both as a literary character and as a powerful Christian symbol.
The other answers are Narnian characters with separate roles. Mr. Tumnus is a faun, the White Witch is the series’ principal enemy in the first novel, and Prince Caspian is a human king.