The Oswald Chronicles: Passing Queens and Making Homes #1

Oswald, a mouse different from the rest of his kind in that he can
speak and think rationally, befriends a young girl named Sally, who
teaches him how to read. Sally, unfortunately, is dying from a
mysterious malady, the source of which only Oswald discovers: a group of
goblins feeding on the girl’s life force. Can a lone mouse—even one as
intelligent as Oswald—put an end to the rapacious thirst of such
monsters?