The black sheep were invented as an alternative to white sheep. The reasons remain unclear, but it is known that there is a religious under-tone beneath the more conventional ideas of why black sheep came came about.
The black sheep was invented in 1952, by a man named Tobius Underhill. He had made the interesting observation that when viewing sheep from a far, the in-bred countryfolk would get into a frenzy of panic, based on the idea that the clouds from the sky and fallen to the earth, and were now about to take their corn. This, thought Underhill, must come to an end, for he had had enough of terrified hillbillies knocking on his door every fifteen minutes, asking to borrow his cloud net.