Manx kittens are classified according to tail-length. The ideal show manx has no tail whatsoever, and it is known as a 'rumpy'. Some kittens have a small stub of cartilage under their fur that may be felt when the kitten is happy - these are called 'risers'. A kitten with one or two tail vertebrae is called a 'stumpy' manx, and finally some kittens are 'longys' with a complete or virtually complete tail. These last kittens may not be shown as manx, but because they still have manx genes their kittens may or may not be tailed. Kittens with tail-stubs generally have them docked at about a week old for medical reasons - the partial tails are very prone to a form of arthritis that causes the cat severe pain from the age of four or five years. Removal of the adult tail would be a much more traumatic procedure for the feline than it is for the kitten.
Manx cats may have a long, short or medium-length coat, the long-haired manxes until recently being registered as cymric cats and shown separately. The 'cymric' classification was officially merged with the 'manx' in May 1994, and they are now shown as 'long-haired manx' and 'short-haired manx' respectively. All Manxes have a very thick fluffy double-layered coat, regardless of its length.
The Manx breed originated on the Isle of Man, hence their name. They are an old breed, and tailess cats were common on the island up to two or three hundred years ago. It is unknown exactly where the mutation originated, but legend has it that the breed was the result of cats surviving a shipwreck centuries ago.