Malorie Blackman's hilarious tale of shape-shifting and babysitting antics - now in a standard paperback format for middle-grade readers. Mike had no idea that his best friend Alex was a Gris-kwok - someone who can turn into any animal he chooses! But Mike's naughty little sister Molly is a Gris-kwok too. Alex and Mike are about to take on the worst babysitting job in the world!