Blinking Dogs of Cheapside

While not unique to the Cheapside area of Old Town, blinking dogs are undeniably more concentrated in that section of the city, thus the name. For the most part, it's impossible to distinguish a blinking dog from any other. They eat, sleeep, play, hunt, bark, and growl just like any other dog. Their nature only becomes apparent when you try to touch them or they try to touch you. At that point, the dog "blinks" out of physical existence, becoming completely incorporeal but still visible as a ghostly apparition. This occurs whether the human or the dog is initiating contact. If you try to pet a blinking dog, it blinks; If a blinking dog tries to bite you or knock you down, it blinks. Only humans trigger this strange phenomenon. When a blinking dog comes into contact with another animal, it remains completely corporeal.
Examples of blinking dogs of nearly every common breeed have been recorded, but the majority are mongrels. They are born to seemingly normal dogs and are generally the only one of their kind in a particular litter. Though many are born as pets, most end up as strays. Their odd condition limits their usefulness as guardians and the lack of physical contact between dog and owner prevents a strong bond from forming, causing the owner to abandon the dog or vice versa.
While certain accounts blame some long-ago Chimerist's experiment for the existence of blinking dogs, the more common explanation is that they are the result of an ancient curse. This story holds that long ago there was an old man living in Cheapside known for being miserly and petty and generally unpleasant toward his neighbors. The only living creatures that the man seemed to have any affectio for was his large collections of dogs, which he let run wild through the neighborhood, further straining relations with the other residents of Cheapside. After some particularly aggregious affront, one of the neighbors (or sometimes a whole group of them) sought the services of a wizard to exact their revenge on the old man. After some consideration, it was decided that the best punishment was to rob him of the solace and comfort that his dogs brought him. The wizard constructed a curse that should have magically prevented the old man from ever again toching or being touched by a dog, but somehow the spell got twisted and affected the dogs rather than the man. While the magic still served its intended purpose, it also created the blinking dogs that still wander the city today.