In Tolkien's legendarium, humans have the unique gift of being able to leave the world after death. However, Tolkien's friend C. S. Lewis had a different conception of the afterlife in his novels. At the end of The Last Battle, the righteous characters find their way to heaven, Aslan's country. This includes humans, centaurs, talking animals and others; they all have immortal souls. And Lewis expressed the same view in his Space Trilogy; the several species of aliens that live on Mars are spiritually coequal to the humans that populate Earth (and Venus).
I just realized though, that this raises a question, because the speaking animals of Narnia can lose their human-like intelligence, if they abuse it. This is mentioned in The Magician's Nephew, when Aslan grants speech to some if the animals. (This appears to be a rare instance of intentional foreshadowing in The Chronicles of Narnia. Lewis rarely had plans for more after the completion of each novel. The exceptions were with The Silver Chair and The Horse and His Boy, for which the writing and editing overlapped; and Lewis was clear that he would not end the series on the prequel The Magician's Nephew.)
Sure enough, in The Last Battle, this actually happens to one of the villains. Ginger the cat loses his power of speech and slightly anthropomorphic shape for his crimes. But what, then, happens to his soul? Is it irrelevant, the souls of Narnia's damned being shortly to be destroyed anyway, when the world comes to an end? Is that consistent with Lewis's Anglican theology? Did the author simply overlook this issue, or did he ever comment on the matter?