As an ancient symbolic Celtic animal, the cat represents the guardian of the Otherworld (or Underworld,lets say each own underworld..).
Stoic, silent and mysterious, cats fit the bill of Otherworld guardians quite well. They keep the secrets of the Otherworld eternally to themselves, as they gaze with guile upon a world that does not see or understand the depth of their knowledge.
Then a black cat…
In Scotland, a strange black cat on your porch is a sign of upcoming prosperity.
In Ireland,when a black cat crosses your path in the moonlight, it means there is going to be an epidemic illness.
In Italy hundreds of years ago, it was believed that if a black cat lay on the bed of a sick person, that person would die.
It is said that a black cat crossing your path is bad luck, but letting one in your house is good luck.
In other folklore, if a cat jumps over a dead body, the corpse will become a vampire. To stop this, the cat has to be killed.
During the catholic inquisition when millions were killed, innocent people were tied to a stake and set aflame with often a black cat was thrown into the fire with them.