Perl’s young champion of all things gluteus returns in an evermore zany salute to the nether regions. As in Chicken Butt! (2009), this book can be read as a duet, although that will only apply to the “up” end of its stated audience for 3-year-olds and up. The text crackles: “Hey, you know what? / In fact, I do! And where and why and how and who. / But, Mom! / I’ll make this crystal clear: no more ‘Chicken Butt!’ my dear…” And Coles’ tickled-pink cartoonish artwork gets right into the mix, the chocolate chip to the cookie dough. The wordplay of inversions allows the boy to find butts aplenty as mother and son roam the aisles of a supermarket, there to find a deer butt, a cat butt, a witch butt, even a bear butt. “Stop right there,” says mom. “But wait!” says her son. “He’s eating under there! / He’s what? Who’s eating under where?” You see where this is going, and the force of gravity leads the text to poop and fart, which may be inevitable but feels like a shopworn laugh at the expense of more loopily inventive repartee. But still, the denouement is so merrily explosive that just to imagine the shrieking voices of a read-aloud is mightily cheering. (Picture book. 3-8)