The intruder froze, feeling a sudden chill. It wasn't a sound that alerted him, but the opposite: the heavy, predatory silence of a trained black guard dog waiting in the dark.

The wizard's familiar was a black dog made of shadow. It didn't bark; it absorbed sound, creating a bubble of pure silence wherever it went.

The hunter's greatest asset was his black dog, which could stalk through the forest with such complete silence that even the birds wouldn't notice its passing.