What is the common way to distinguish the Manx cat because of the cat body-type mutation?
Manx cat The Manx cat ( , in earlier times often spelled Manks), is a breed of domestic cat ("Felis catus") originating on the Isle of Man, with a naturally occurring mutation that shortens the tail. Many Manx have a small stub of a tail, but Manx cats are best known as being entirely tailless; this is the most distinguishing characteristic of the breed, along with elongated hind legs and a rounded head. Manx cats come in all coat colours and patterns, though all-white specimens are rare, and the coat range of the original stock was more limited. Long-haired variants are sometimes considered a separate breed, the Cymric. Manx are prized as skilled hunters, and thus have often been sought by farmers with rodent problems, and been a preferred ship's cat breed. They are said to be social, tame and active. An old local term for the cats on their home island is stubbin. Manx have been exhibited in cat shows since the 1800s, with the first known breed standard published in 1903.
Anthracite budgerigar mutation The Anthracite budgerigar mutation is an extremely rare mutation that occurs in the budgerigar. The mutation, similar to the Violet budgerigar mutation, causes a difference in the coloring of budgerigars. Anthracites have black or very dark gray feathers, possibly with some white depending on the budgerigar in particular. The mutation is believed to have started in Germany, and tends to be local to that area. Currently, most owners wishing to obtain an Anthracite need to import these budgerigars from Germany.