It is very possible that the novice gravedigger that Brienne encounters at the Monastery on the Quiet Island is in fact Sandor Clegane. As he has a similar wound to the one the hound recived and is wearing a scarf that covers his face so his scars would not have been seen.
I really want this to be true
“She don’t speak,” said the big man in the yellow cloak. “You bloody bastards cut her throat too deep for that. But she remembers.”
The surreal forests of Romania, by Andrei and Sergiu Cosma of PhotoCosma.