Oz in Jeopardy! calendar edition

My Jeopardy! daily calendar has this clue today, in the category Pets in Fiction:

A CLASSIC 1900 BOOK
SAYS HE "WAS NOT GRAY;
HE WAS A LITTLE BLACK DOG,
WITH LONG, SILKY HAIR"

Turn the page over to see the correct response, and of course it says, "WHO IS TOTO?"