Stink by Jenny McLachlan

Danny Todd is desperate to be normal and fit in at school so he isn’t happy when he opens a fairy door and a REAL fairy flies out. Stink turns Danny’s life upside down. She hides in his hair, swims in his cereal, rides his rats and accidentally shrinks his best friend.

Danny HAS to get rid of Stink, but she won’t go away until he’s helped her earn gold nuggets to get new wings. Can Danny help Stink do a good deed or is he going to be stuck with his fairy forever?