In a large bowl, whisk together the chocolate pudding mix and cold milk until smooth and thickened, about 2 minutes.
Fold the whipped topping into the pudding mixture until fully combined and creamy.
Crush the chocolate sandwich cookies into fine crumbs using a food processor or by placing them in a sealed bag and crushing with a rolling pin.
Add a spoonful of cookie crumbs to the bottom of each dessert cup.
Spoon a layer of the chocolate pudding mixture over the cookie crumbs.
Repeat the layers until the cups are filled, finishing with a layer of cookie crumbs on top.
Decorate each dirt cup with gummy worms, candy pumpkins, candy eyes, or your favorite Halloween candies.
Refrigerate for at least 30 minutes before serving to allow the flavors to meld.
Serve chilled and enjoy.