What, indeed? There are an astounding number of black cats living among us worldwide... sometimes maligned, sometimes treasured, some pedigreed and pampered, some without papers but cherished all the more for that.
What IS a magic black cat? Is your cat one of them? Perhaps... but remember, magic is perverse, and defies definition. If we say that magic black cats are short-haired Siamese-wannabes, the cry will go up from the long-haired contingent, "But what about MY cat? She's just as incredible as yours!"
Similarly, if we say that magic blacks are most definitely of the non-pedigreed nature, the owners of sleek Bombays, imposing Maine Coons, angular Oriental Shorthairs, plush Exotic Shorthairs, and companionable British and American Shorthairs will rise up in fury. It's true that magic blacks are God's great boon to the non-pedigreed cat; I'd stake my reputation on the fact that more magic blacks exist among the unpapered populace than in any CFA royal court... but it would be meanspirited to exclude them, and magic, at any rate, won't be denied.
But what IS a magic black cat? The best definition I've found comes out of a fabulous book by Barbara Holland, hard to find on the shelf but certainly still in circulation, called Secrets of the Cat: Its Lore, Legend, and Lives. So taken am I by this book, and so hard is it to find, that I've quoted liberally from it... may I be forever forgiven, since I don't mean to plagirize, and want to give credit where credit is due.
There's a recognized cat called the Oriental Shorthair, billed as a knowlegdeable blend of Siamese, American Shorthair, Colorpoint Shorthair, and other judicious ingredients, and it comes in exotic colors like Silver and Cameo Smoke, but that's not what we're talking about at all. The cats under consideration are black, and accidental. Once source refers to a "royal cross," a splendid black sometimes produced from careful Siamese/Burmese mixing. That's not it, either.
... Most owners of magic black cats take it for granted that they're half or part Siamese, but not in one single case have I found a person who could prove it or even reasonably assure it... The magic black cats are changelings in the cradles of commoners. They come from the shelters; they come in off the streets, ripping furiously at the back door and shouting for admission; they are born among ordinary kittens. The little black cat who lives here now was born in a section of the country where no Siamese genes could be supposed to float among the population; dog and horse country, where any human owning a Siamese would be stoned clear to the county line. Her mother is a dumpy, fluffy, round-faced little person in gray stripes; she herself is one of those cats.
They stand out in a litter. Their ears are large and open with a bald patch running down to the eyes, and their tails are long and thin. At an age when other kittens look like stuffed toys, they look like six pieces of oiled black string...
These cats are exceptionally alert, brave, bossy, curious, and agile, and figure out ways to get into trouble that never occurred to the other cats in the house. They're clever with their hands and use their mouths as an extra hand. While still quite small they take over the sacred places of the other cats. They eat like young wolves and get longer and heavier but no rounder... when the baby fluff gives way to proper fur they look like wrought iron and shine like polished coal...
...With the right person, when they grow up they develop an exclusive, passionately possessive relationship, not always demonstrative but unmistakeable. It's risky to leave them for long periods and criminal to give them away.
- Barbara Holland, Secrets of the Cat (Ballantine Books, June 1989)