The Glass Cat, which Dr. Pipt lawlessly made, continued the Wizard, is a pretty cat, but its pink brains made it so conceited that it was a disagreeable companion to everyone. So the other day I took away the pink brains and replaced them with transparent ones, and now the Glass Cat is so modest and well behaved that Ozma has decided to keep her in the palace as a pet.
ó L. Frank Baum, The Patchwork Girl of Oz