American Curl, rare United States breed of cat, the result of a genetic mutation that causes the ears to curl backwards. The first American curl was Shulamith, a longhaired, mixed-breed female found in California in 1981. Shulamith's ears were not straight, like normal ears, but were curled backwards; she was otherwise normal, since the gene does not affect the rest of the cat. All American curls are descended from Shulamith. In a typical American curl litter, half the kittens have curled ears.
An American curl's ears curve in a gentle curl toward the back of its head. The ears are firm to the touch. The American curl is a medium-sized cat with a medium-long, silky coat. It comes in a wide range of colors. The American curl also comes in a shorthaired variety called the American curl shorthair.