Childhood movie about boy dreaming about a train headed for him
Okay, in this animated film of the 90's I'm guessing, the boy goes into this world and befriends this big guy who is the leader of the world. This big guy loves toys. He tells the little boy about a key that unlocks everything and he entrusts him with it. Later on some little dude convinces the little boy to open a door, and its like, the door to all evil. Inside is this black cloud that corrupts everything it touches. To travel the kid has a flying bed and has to lock up the cloud when the big leader guy cant. I also remember that in like, one of the first scenes he's dreaming and he hears something knocking on his door, and when he opens it, it's a train headed straight for him. But he wakes up before it hits.
Any help would be appreciated!
