When you approach the entrance to the witch's cave, there is a random chance that Batman's Batmobile will drive out of it. Type LOOK CAR to get a funny comment about it being lost and not belonging in the story.
Debug Mode
Hold [Alt] and press D. Release both keys and press [Enter] twice to enable debug mode. Type get object and press [Enter]. Enter a number at the "Object Number" prompt to receive an item. To teleport, type tp after enabling debug mode. Enter a number at the prompt to travel to the corresponding location.