Mackerel is the original pattern and is by far the most common tabby pattern. The legs and tail have dark bars as do the cat's cheeks. A "mackerel tabby" has narrow stripes that run in parallel down its sides. This is what some people refer to as a "tiger." An "M" shape appears on the forehead along with dark lines across the cat's cheeks to the corners of its eyes. Mackerels are also called 'Fishbone tabbies' probably because of the mackerel fish. A mackerel tabby pattern is the only striped coat pattern seen in domestic cats.