A tabby cat, or simply tabby, is any domestic cat (Felis catus) with a distinctive 'M'-shaped marking on its forehead; stripes by its eyes and across its cheeks, along its back, and around its legs and tail; and characteristic striped, dotted, lined, flecked, banded, or swirled patterns on the body—neck, shoulders, sides, flanks, chest, and abdomen.
"Tabby" is not a breed of cat, but a coat pattern found in many official cat breeds, and is very common among the general population of mixed-breed cats around the world. The tabby pattern occurs naturally and is connected both to the coat of the domestic cat's direct ancestor and to those of their close relatives: the African wildcat (Felis lybica lybica), the European wildcat (Felis silvestris) and the Asiatic wildcat (Felis lybica ornata), all of which have similar coats, both by pattern and coloration. One genetic study of domestic cats found at least five founders.
Etymology
The English term tabby originally referred to "striped silk taffeta", from the French word tabis, meaning "a rich watered silk". This can be further traced to the Middle French atabis (14th century), which stemmed from the Arabic term عتابية / ʿattābiyya. This word is a reference to the Attabiya district of Baghdad, noted for its striped cloth and silk; itself named after the Umayyad Governor of Mecca Attab ibn Asid. Such silk cloth became popular in the Muslim world and spread to England, where the word "tabby" became commonly used in the 17th and 18th centuries.
Use of the term tabby cat for a cat with a striped coat began in the 1690s and was shortened to tabby in 1774. The notion that tabby indicates a female cat may be due to the feminine proper name Tabby as a nickname of "Tabitha".
Patterns
The four known distinct patterns, each having a sound genetic explanation, are the mackerel, classic, ticked, and spotted tabby patterns.
A fifth pattern is formed by any of the four basic patterns being included as part of a patched pattern. A patched tabby is a cat with calico or tortoiseshell markings combined with patches of tabby coat (such cats are called caliby and torbie, respectively, in cat fancy).
All five patterns have been observed in random-bred populations. Several additional patterns are found in specific breeds and so are not as well known. For example, a modified classic tabby is found in the Sokoke breed. Some of these rarer patterns are because of the interaction of wild and domestic genes, as with the rosette and marbled patterns found in the Bengal breed.
Mackerel (striped) tabby
The mackerel, or striped, tabby pattern is made up of thin vertical, gently curving stripes on the sides of the body. These stripes can be continuous or broken into bars and short segments/spots, especially on the flanks and stomach. Three or five vertical lines in an "M" shape almost always appear on the forehead, along with dark lines from the corners of the eyes, one or more crossing each cheek, and of course many stripes and lines at various angles on the neck and shoulder area, on the flanks, and around the legs and tail, marks which are more or less perpendicular to the length of the body part. Mackerel tabbies are also called 'fishbone tabbies,' probably doubly named after the mackerel fish. Mackerels are the most common among tabbies.
Classic (blotched) tabby
The classic tabby, also known as blotched tabby, has the 'M' pattern on the forehead but, rather than primarily thin stripes or spots, the body markings are thick curving bands in whorls or a swirled pattern, with a distinctive mark on each side of the body resembling a bullseye. 80% of modern-day cats have the recessive allele responsible for the classic pattern. Black tabbies generally have dark browns, olives, and ochres that stand out more against their black colors. Classic tabbies each have a light-colored "butterfly" pattern on the shoulders and three thin stripes (the center stripe being the darkest) running along the spine. The legs, tail, and cheeks of a classic tabby have thick stripes, bands, and/or bars. The gene responsible for the coloring of a classic tabby is recessive. Many American shorthair cats demonstrate this pattern.