The Last Firefox by Lee Newbury

Between bullies at school and changes at home, Charlie Challinor finds life a bit scary. And when he's made guardian of a furry fox cub called Cadno, things get a whole lot scarier. Cadno isn't just any fox: he's a firefox -only one of his kind - and a hunter on his trail. Charlie's going to need to find the bravery he never thought he had, if he's going to save the last firefox.....