Step 1) Found a box that was the size and shape of what I was looking for. I was lucky in that the Creeper I was making is just a rectangle. Then I spray-painted the box so it was a uniform color and so the wording and pictures didn't show through.
Step 4) Once the crepe paper is covering the entire box, I glued the face of the creeper on. You can still see the glue drying, but you get the idea.
Step 5) When the glue is dry, turn the box upside down and cut a 3x3 inch hole on the bottom of the box. Only cut three sides, so that it hinges. I just used a serrated steak knife for that. Then I glued some crepe paper around the edges of the cut of the trap door, so that it looked finished.
Step 6) Poke a hole through the middle of the trap door, and take a ribbon and pass it through. Tie a knot at the end of the ribbon large enough so that one end cannot go through the hole. I used green for the "real ribbon" and then glued the "fake ribbons" around it. Tall Boy will get the green ribbon, of course!
Step 7) Wait for the glue to dry and then add the candy! Push the trap door closed, it should close very well with the added crepe paper around the edges of the trap door. Voila, done!