Process 20 cookies in food processor or blender until finely crushed. Add 2 to 3 tablespoons milk; process until crumbs begin to hold together. Press into 9-inch pie dish.
With hand mixer, beat instant pudding and pie filling, 1 cup milk and creme de menthe (see Note) in bowl until thickened and smooth. Fold in whipped topping. Chop remaining 8 sandwich cookies; fold into pudding mixture.
Spoon filling into crust, swirling top decoratively. Refrigerate 2 hours or as long as overnight.