Stir cold milk and pudding mix together and mix well. Put in fridge to thicken.
Beat softened cream cheese until creamy. Slowly add the whipped topping, beating after each addition.
Put 10 of the oreo cookies in a freezer bag and crush with a rolling pin. Reserve the other 8 for a garnish. Set aside.
When the pudding has thickened, add it to the cream cheese mixture and beat until well incorporated.
Add the coarsely-chopped oreos and stir well to incorporate.
Pour the mixture into the pie shell. Chill for at least 3- 1/2 hours or overnight.
Just before serving, place hot fudge in a small Ziploc sandwhich bag. Warm in the microwave for 10-15 seconds or until it is soft enough to drizzle. Using scissors, cut a small hole in one corner of the bag. Drizzle hot fudge over pie by squeezing it out of the whole in a zig-zag shape over the pie.
Garnish each slice with an oreo and additional whipped topping, if desired.