"There are some dogs which, when you meet them, remind you that, despite thousands of years of man-made evolution, every dog is still only two meals away from being a wolf. These dogs advance deliberately, purposefully, the wilderness made flesh, their teeth yellow, their breath a-stink, while in the distance their owners witter, "He's an old soppy really, just poke him if he's a nuisance," and in the green of their eyes the red campfires of the Pleistocene gleam and flicker…
This dog would make even a dog like that slink nonchalantly behind the sofa and pretend to be extremely preoccupied with its rubber bone."
- Good Omens, by Terry Pratchett and Neil Gaiman.