Black cat gifts, merchandise and collectibles. The folklore surrounding black cats varies from culture to culture. In Great Britain, black cats are seen as lucky and are often given in token form to brides. The Scottish believe that a strange black cat's arrival to the home signifies prosperity. In Celtic mythology, a fairy known as the Cat Sėth takes the form of a black cat. Black cats are also considered good luck in Japan. Furthermore, it is believed that a lady who owns a black cat will have many suitors.