By Sandra Boynton
The animals are all off having fun together — a hog and a frog, a cat and some rats — but not the hippopotamus. She hangs back and watches, page after page, until the others turn around and ask her in.
Everybody's busy having a good time. A hog and a frog splash around in the bog, a cat and two rats try on hats, a moose and a goose share some juice. And every bouncy little scene ends the same way: 'but not the hippopotamus.' She's off to the side, watching the fun, left out again and again. Then the others finally call over, 'Come join the lot of us!' — and she does, in a happy gallop. The last page has one more joke waiting: now it's the armadillo hanging back. The whole book is a rhyme about being on the outside and the relief of getting asked in, told so lightly your one-year-old mostly just hears the silly words and the happy ending.
Under the bounce there's a real little story: being left out, then being welcomed in. It never actually says the word 'friendship,' but that's what it's about, and even the youngest children can feel that shape without anyone explaining it. Boynton keeps it so light that it reads as warmth rather than worry, which makes it an easy one to reach for if your child tends to hang back at the playground. The refrain hands them a line to chime in on, and the armadillo joke at the end pays them back for sticking with it all the way through.