Charlie McGuffin has an incredible secret . . .

He can change into animals. All sorts of animals: a flea, a pigeon, even a rhino. Trouble is, he can't decide when - it only happens when he gets worried.

And right now, Charlie has quite a lot to worry about:* His brother (who is in hospital)* His parents (who are panicking about it)* And the school bully (who has Charlie in his sights)And even though every kid wants a superhero power, Charlie isn't keen on changing into a chicken in the middle of the school play. So with the help of his three best friends, Charlie needs to find a way of dealing with his crazy new power - and fast!