Calico describes a coat, not a breed: white with patches of black and orange, or soft gray and cream in the dilute version. The pattern shows up in domestic shorthairs and longhairs as well as many pedigreed breeds. Because the orange and black color gene sits on the X chromosome, nearly every calico is female, and the rare males usually carry an extra X chromosome.
A calico's size, coat and health follow whatever she's made of, which in most cases is a domestic shorthair weighing roughly 6 to 12 pounds and living 12 to 18 years. Shedding is moderate. Folklore credits calicos with attitude, but coat color hasn't been shown to predict personality, so meet the cat in front of you and watch how she handles people and play.