I was pointed to the Sunken Castles, Evil Poodles collection by an anonymous commenter on a post I made on little_details asking for help researching German folklore and folkways.

I was already aware that poodles, despite their modern association with France, are descended from German water-dogs, where they are known as pudels - I did a research paper on poodles in elementary school. And, I had once read a more obscure fairy tale from the Grimm Brothers' collection, "the Pink", which involves the transmogrification of its antagonist into a fire-vomiting black poodle as punishment by the main character, and wondered at the odd specificity of the form imposed. Jürgen Hubert's translations of non-fairytale folklore into English makes it clear that the firey black poodle (often implicitly or explicitly a ghost or demon) is a wider motif in German folk stories.

One can compare these stories to host/devil-dog folklore of the British isles - the stuff the average English-speaker has most access to. But the Grims, Shucks, etc of those stories are not, to my memory, associated with specific breeds, landraces, or types of dogs.

The narrator of this video suggests that perhaps part of the reason poodles, specifically, are so common in German black-dog stories is that poodles are known for their intelligence, relative to other docks, and thus one could imagine a human or demonic intellect inhabiting that form. And standards poodles - when not shaved into fancy cuts - are awkward, shaggy creatures, looking weirdly muppetlike when I see them bounce and run around. It's comical in the daylight, but I can see how it would be unnerving to see from a feral animal lit only by lamplight.