'go away bad dream'

Every night my son would come running to my bed shaking beacause he had a bad dream. I asked him about the dream and he said that a tickle monster would chase after him and try to hurt him. So I asked if he would draw this tickle monster. He immediately jumped up and started to draw a picture of him. This monster was very scary with big sharp teeth, black eyes and knives and chain saws coming off of its body. It scared me too, so I asked him if he could think of a way to get rid of this monster from his dreams. He sat and thought for a moment and proceeded to go to the draw and he pulled out an envelope. He then folded the drawing in three making sure that the picture could not be seen, he put it in the envelope, sealed it and then went to his bedroom and put it in his top drawer and closed it. He looked at me and said "Mom, he's trapped now". That night he did not have the dream. The next morning he took the envelope out of the draw and took it to school. I asked him what he did with it and he told me that he gave it to another boy in his class. It's been nearly a year 'tickle monster' free. I realized no matter what I said to him to try and make him realize that it was just a dream, to him it was real and HE was the only one who could fix it!