Use your hands to break up the cookies. You can crush them in a food processor or put them in a large plastic bag and crush them using a rolling pin.
Put the cold milk in a bowl and add the pudding mixes. Use a wire whisk to mix together. Once the pudding is smooth, add in 3 cups of thawed Cool Whip and 1/2 of the crushed cookies. Use a spoon to fold everything together.
Spoon the pudding mixture into a large plastic bag and cut off a corner of the bottom of the bag. Pipe the pudding into individual cups until they are 2/3 full. Cover the top with crushed cookies. Put this in the refrigerator until you are ready to serve.
A half an hour before dinner, take the pudding out of the refrigerator and put the left over Cool Whip in a plastic bag. Cut off a corner of the bottom of the bag and pipe ghosts on the top of each cup. Place chocolate chips, pointed side in, to create eyes and then place a pumpkin on the ground next to the ghost.