Reepicheep is described as a "gay and martial mouse",[1] about two feet high when standing on his hind legs,[2] with ears "nearly as long as (though broader than) a rabbit's";[1] small Talking Beasts in Narnia are very much larger than their "dumb" counterparts.

Lucy heals his wounds with her magic cordial, but he finds when he rises to address Aslan that his tail has not regrown, and he apologizes for appearing in such a dishonourable state.

The only Talking Beast amongst the titular ship's crew, Reepicheep reveals that he has been driven since infancy by a vision of finding Aslan's Country across the sea in the far east of the Narnian world.

His aspirations and code of honour bring him into conflict early with the egregious Eustace, but when the latter is turned into a dragon by a curse, Reepicheep becomes his chief friend and comforter.

[6] As a model both of ferocity on the battlefield and of courtesy in polite society, Reepicheep embodies the knightly ideal Lewis prescribes for manhood in his 1940 essay The Necessity of Chivalry.