The following is from Wikipedia:
"The folklore surrounding black cats varies from culture to culture. In great Britain and in Ireland, black cats are a symbol of good luck. The Scottish believe that a strange black cat's arrival to the home signifies prosperity. Black cats are also good luck in Japan. Furthermore, it is believed that a lady who owns a black cat will have many suitors. However in Western history, black cats have often been looked upon as a symbol of evil omens, specifically being suspected of being the familiars of witches, and so most of western and southern Europe considers the black cat as a symbol of bad luck, especially if one crosses paths with a person, which is believed to be an omen of misfortune and death. In Germany, some belive that black cats crossing a person's path from right to left, is a bad omen, But from left to right, the cat is granting favorable times."
