The great lion in C.S. Lewis’s Narnia books is Aslan.
Aslan is the central recurring figure in The Chronicles of Narnia. He is the son of the Emperor-Beyond-the-Sea and the creator of Narnia, and he appears as a wise, powerful, and compassionate lion. His name is derived from the Turkish word for “lion.”
Aslan’s role changes from book to book. He guides characters, restores justice, and helps defend Narnia against threats such as the White Witch. In The Lion, the Witch and the Wardrobe, he gives his life in Edmund’s place and returns to life, a plot element that is widely understood as Christian allegory.
Aslan is not the same character as King Caspian, Prince Rilian, or Puddleglum. Those are human or marsh-wiggle characters who belong to different parts of the Narnia narrative.