Tailless cats, then called stubbin (apparently both singular and plural) in colloquial Manx language, were known by the early 19th century as cats from the Isle of Man (Mann), hence the name, where they remain a substantial but declining percentage of the local cat population. The taillessness arose as a natural mutation on the island, though folklore persists that tailless domestic cats were brought there by sea. They are descended from mainland stock of obscure origin. Like all house cats, including nearby British and Irish populations, they are ultimately descended from the African wildcat (F. silvestris lybica) and not from native European wildcats (F. s. silvestris), of which the island has long been devoid.
The dominant trait of taillessness arises from a spontaneous mutation, the Manx taillessness gene, that eventually became common on the island because of the limited genetic diversity of island biogeography (an example of the founder effect and, at the sub-specific level, of the species-area curve).[verification needed]
In the Manx language, the modern name of the breed is kayt Manninagh literally 'cat of Mann' (plural kiyt or kit), or kayt cuttagh lit. 'bob-tailed cat'. Kayt, used as both a masculine and feminine noun, is also encountered as cayt, and depending on the exact construction, it may be lenited as chayt or gayt.:138 The diminutive word is pishin or pishyn, 'kitten' (with various plurals). Manx itself was often spelled Manks in English well into the late 1800s.
There are numerous folktales about the Manx cat, all of them of "relatively recent origin";:7 they are focused entirely on the lack of a tail, and are devoid of religious, philosophical, or mythical aspects found in the traditional Irish–Norse folklore of the native Manx culture, and in legends about cats from other parts of the world.:7
The name of the promontory Spanish Head on the coast of the island is often thought to have arisen from the local tale of a ship of the Spanish Armada foundering in the area, though there is no evidence to suggest this actually occurred. Folklore has further claimed that a tailless cat swam ashore from said shipwreck, and thus brought the trait to the island. However, tailless cats are not commonly known in Spain, even if such a shipwreck were proven.
Regardless of the genetic and historical reality, there are various fanciful Lamarckian folktales that seek to explain why the Manx has a truncated tail. In one of them, the biblical Noah closed the door of the Ark when it began to rain, and accidentally cut off the tail of the Manx cat who had almost been left behind. Over the years a number of cartoons have appeared on postcards from the Isle of Man showing scenes in which a cat's tail is being run over and severed by a variety of means including a motorcycle, a reference to motorcycle racing being popular on the island, and an update of the Noah story. Because the gene is so dominant and "invades" other breeds when crossed (often without owner knowledge) with the Manx, there was a folk belief that simply being in the proximity of a Manx cat could cause other breeds to somehow produce tailless kittens.
Another genetically impossible account claimed that the Manx was the hybrid offspring of a cat and a rabbit, purporting to explain why it has no or little tail, long hind legs and a sometimes hopping gait. The cat-rabbit halfbreed tale has been further reinforced by the more widespread "cabbit" folktale.
Populations of tailless cats also exist in a few other places in Europe, most notably Cornwall, only 250 miles (400 km) from the Isle of Man. A population on the small, isolated Danish peninsula (former island) of Reersø in the Great Belt may be due to the arrival on the island of cats of Manx origin, by ship. Similar cats are also found in Crimea, a near-island peninsula in the Black Sea, though whether they are genetically related to maritime Manx cats or are a coincidentally similar result of insular genetic diversity limitations, like the unrelated Kuril Islands Bobtail, Karelian Bobtail, Japanese Bobtail, and Indonesian Lombok cats, is unknown. The Manx gene may be related to the similarly dominant tail suppression gene of the recent American Bobtail breed, but Manx, Japanese Bobtails and other short-tailed cats are not used in its breeding program, and the mutation seems to have appeared in the breed spontaneously. Possible relation to the Pixie-bob breed, which also ranges from rumpy to fully tailed, is unknown.