Knock, Knock It's Halloween!

A plastic knocker shaped like a jack-o'-lantern is affixed to the inside of the extra-long back cover included in Knock, Knock It's Halloween by Betty Schwartz, illus. by Barry Gott, so youngsters can knock away as they relate the more than 20 jokes here (""Knock, knock/ Who's there?/ Dismay./ Dismay who?/ Dismay seem/ funny to you,/ but I'm scared!""). (