"Charlie McGuffin has an incredible secret... He can change into animals. All sorts of animals, in fact: a flea, a pigeon, even a rhino. Trouble is, it only happens when he gets worried, and right now, Charlie has quite a lot to worry about: His brother (who's in hospital) His parents (who are panicking) And the school bully (who has Charlie in his sights) With the help of his three best friends, Charlie needs to find a way to deal with his crazy new power - and fast."