Charles, the crocodile who swallowed everything in Keep Your Mouth Closed, Dear (1966), now can't keep his mind on anything--so (absent-mindedly?) he gives the cheese in Father's sandwich to Minnie the mouse, the bread to the assembled doves, and the empty plate to Father. Or, on his first day at school, Charles builds with paints, sculpts the soap, and paints the blocks. (He also sleeps through the class story: ""I always sleep when Mother reads me a bedtime story."") Assorted miscues later, Mother is ""exhausted, done in, and near collapse."" Father counsels patience--and then, on Charles' birthday, produces just the present to capture his imagination and keep his mind from straying: an invisible thinking cap. The crocodiles are variously beseeching or crestfallen or agape (never a blank); Charles' quips are witty--and lightly self-mocking too; in black-and-white with apple-green (for the crocs, of course), the book looks as crisp and lively as it reads.