''black sheep'' = ''black goat''? In the novel A SONG OF ICE AND FIRE，there's a frase goes:... During one of their louder quarrels, when Catelyn was eight, Lord Hoster has called Brynden "the black goat of the Tully flock."..... In my understanding, Brynden is the "black sheep " of the Tullys'. So, does "black sheep" equal to "black goat"???