In a mixing bowl, combine pudding and peanut butter; stir until smooth. Fold in whipped topping; stir until completely blended.
Pour filling into pie crust. Freeze pie until firm. Partially thaw in refrigerator, for about 2 hours or so, before serving. You can store leftovers in the refrigerator or freezer. Leftover pie sometimes gets a little soft in the refrigerator, and doesn't hold its shape. It still tastes good, though. If you want perfect looking slices after you make the first incision, store in freezer and thaw as needed.