"Please would you tell me", said Alice, a little timidly, for she was not quite sure whether it was good manners for her to speak first, "why your cat grins like that?"
"It's a Cheshire-Cat," said the Duchess, "and that's why. Pig!"
She said the last word with such sudden violence that Alice quite jumped;
but she saw in another moment that it was addressed to the baby, and not to her, so she took courage, and went on again: -
"I didn't know that Cheshire-Cats always grinned; in fact, I didn't know that cats could grin."
"They all can," said the Duchess, "and most of'em do."

Alice's Adventures in Wonderland, Lewis Carroll