One of my favorite books when I was a child. It's very cute and is supposed to help children become more comfortable with using the potty. Some versions have a boy on the cover and some a girl.
This is the GIRLS' version. Simply the best toilet-training book I found - I used it for both my girls (now ages 16 & 6). I think it's smarmy & awful, but they both adored it & this book was what finally did the trick for both of them, ten years apart!