Title of a children's movie
There has been a question bugging me forever and I think that I have even been having dreams about the movie, I saw it when I was a kid though and I cannot remember the title. It was about this boy and he traveled to a different magical world, and he traveled on his bed, I believe and I remember there being some significane about a train. This other world was very elaborate and I think it was located in the sky, and the boy became friends with the princess. There was a bad guy, and he could change shapes into like this blob thing, and he overtook the king. This was a cartoon movie and I know I am not just dreaming this up, this is a real movie. If anyone has any ideas what this movie could be, please post something! What is this movie called?