More like:
You encounter some mutated cows
Cow: Moo
Cow: Moo i say moo
Also if you are played fallout you would run into some place called "Bobs Car dealership".
You would talk to Bob and he would keep talking abut how he can sell you a car, then if you agree to buy and ask for a free tank of gas he will say"Sorry we don't have an petrol."