Meet Mr. and Mrs. Twit. This nasty couple likel to play tricks on each other. She feeds him worms instead of spaghetti. He slips a frog in her bed. On and on, each prank is more terrible than the one that came before. And here are the Muggle- Wumps - a nice family of monkeys whom the Twits are training for the first Great Upside- Down Monkey Circus. The Muggle-Wumps don't like that very much, so the Muggle-Wumps, along with the Roly-Poly Bird, give the Twits the nastiest, the biggest, most horrible suprise of all.