In a large mixing bowl, combine the 4 cups of milk and the two boxes of instant chocolate pudding mix. Whisk together until the mixture is smooth and begins to thicken, which should take about 2 minutes.
Once the pudding is thick, gently fold in the 8 ounces of whipped topping.
Take your chocolate sandwich cookies and crush them into fine crumbs.
In your serving cups, start with a layer of the chocolate pudding mixture, followed by a generous layer of crushed cookies. Repeat these layers until your cups are filled, finishing with a layer of whipped topping on top.
Place 3-5 gummy worms on top of each cup for a whimsical touch.
Place the assembled cups in the refrigerator for at least 1 hour to allow the flavors to meld together. Serve chilled and enjoy!