Tortoiseshell and Calico

This cat is also known as a Calimanco cat or Clouded Tiger cat, and by the nickname "tortie". In the cat fancy, a tortoiseshell cat is randomly patched over with red (or its dilute form, cream) and black (or its dilute blue) mottled throughout the coat. Additionally, the cat may have white spots in its fur, which make it a "tortoiseshell and white" cat or, if there is a significant amount of white in the fur and the red and black colors form a patchwork rather than a mottled aspect, the cat will be called a "calico". All calicos are tortoiseshell (as they carry both black and red), but not all tortoiseshells are calicos (which requires a significant amount of white in the fur and patching rather than mottling of the colors).

Source : http://en.wikipedia.org/wiki/Cat