The Dream Tree by Winfried Wolf is an older book that my kids LOVE! It's a repeat read in our house. It's probably not even in print anymore and we purchased it at a second hand store that carried old, unused library books. It's about a little boy named Michael who can't sleep. He sees ghosts, witches, giants, and magicians prowling around his bed. He decides that enough is enough. He uses his imagination to take care of them and has fun doing it.