There, on our favourite seat, the silver light of the moon struck a half-reclining figure, snowy white… something dark stood behind the seat where the white figure shone, and bent over it. What it was, whether man or beast, I could not tell.
-Bram Stoker, Chapter 8, Dracula.
Put another way, I saw this image by the brilliant Becky Cloonan and immediately this bit wrote itself, just wrote itself (and, yeah, needs revising):
”As he went, treading along the ground, along the earth, there came with him, opposite him, walking upside down within the earth, on the ground as if it were a ceiling, a damnable beast with no obligation to sense or space or natural order. He was a human, thin and ragged and striding with greasy grace. It was a wolf, thin-legged and bristling with spiky fur, picking its way through the dirt and darkness below, two steps for his every one, clinging to the roof below.
"They came about together, joined at the shadows, hunting in their fashion, smiling in their fashion, their breath clouding in the cold."