The Three Legged Chicken

A man was driving up the interstate late one night when he was amazed to see a weird creature overtake him at a great speed. He accelerated in an attempt to catch up with it, but the creature was far too quick for it him and he dimly saw it run off a highway at an exit. The driver followed, only to see it jump over a hedge and disappear into some woods. Nearby stood a farmhouse; the driver stopped his car, walked up to the door and knocked. 
The driver apologised to the farmer for bothering him and asked him about the creature. 'Oh yes,' said the farmer, 'that's one of my specially bred three-legged chickens. I bred them so that when we have roast chicken for dinner, my wife,my son and myself can have a chicken leg each.' 

'Really?' asked the man. 'That's interesting. How do they taste?' 

'I don't know,' replied the farmer. 'I have not been able to catch one yet.'