Black dogs

         Black dogs are primarily nocturnal apparitions. said to be associated with the devil or in European mythology with death. Some examples would be Cwn Annwn, Garmr, and the more widely known Cerberus. All of those were guardians of the "underworld." So black dogs are almost universally accepted to being a malevolent spirit. So why is it eight years and nothing has happened? Clearly I'm either crazy, seeing things, or it's something completely different.