''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"???

Question

''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"???

Answer

I am not sure why you make that assumption. "Black sheep" means a non-conforming member of a family, a flock, to complete the idiom in this case. The term may even mean someone who is disfavored. "Black goat" is not an idiom with which I am familiar.

Answer

I've got no idea what a "black goat" is. My feeling is that it is not the same as a "black sheep".

Answer

Yes.