Put chocolate wafers into a large plastic bag. With a rolling pin, crush the cookies into a fine crumb and set aside.
Set aside 9 Snickers minuatures and roughly chop the remaining bars. Place in a mixing bowl and set aside.
Chop the Twix fun-size bars and place in a separate mixing bowl and set aside.
Prepare the pudding according to the directions on the package. Refrigerate for 10 minutes.
Fold the whipped topping into the pudding.
Line bottom of pan with chopped Snickers.
Spoon half of pudding mixture over candy, then sprinkle with Twix and top with remaining pudding.
Spread chocolate wafer crumbs over the entire surface, mounding some of the crumbs in different areas to make hills.
Use M&M's to make a path.
Decorate the remaining 9 Snickers with white icing and press the bars into the surface creating tombstones.