Where would a witch be without her black cat? Well, if you were to ask the ancient Celts, the would tell you that it is a soul that has been reincarnated. Moving onto when Christianity began to spread across Europe, it was believed that a black cat was a witches familiar. The being in which the soul of the witch had taken form. This is why there are so many photos of witches with black cats, their soul is right there with them. Black cats are a part of Halloween with the ancient folklore and legends that came from long ago.