It is possible for a Manx to have anything from a full tail to nothing but a small indentation where the tail would be. A Manx cat’s tail length falls within four classifications: A rumpy classification indicates no tail whatsoever. A Manx classified as a riser or rumpy riser has a slight “stub” at the base of the spine. A stumpy Manx has a small partial tail. Finally, a tailed or longy Manx will have a complete or nearly complete tail.
While a Manx must fall within either the rumpy or riser classification in order to be considered for showing, the tailed Manx is necessary for avoiding genetic complications. This is due to the dominant gene that is responsible for the Manx’s lack of tail. A Manx with two copies of this dominant gene is at extremely high risk for side effects due to the over-shortening of the spine. It is for this reason that rumpy or tailless Manx cats are always bred with a tailed Manx to minimize the risk of genetic defect. As a result , a litter of Manx kittens will usually include varying tail lengths.
Other notable physical characteristics of the Manx include hind legs that extend much farther than the front legs. Besides making the Manx appear to walk with a noticeable hop the hind legs of this breed give it considerable jumping power. A Manx cat is capable of making vertical jumps much higher than other cat breeds. It is not uncommon for a Manx owner to report his cat regularly ending up on top of the fridge.<ref>http://www.cfainc.org/breeds/profiles/manx.html</ref>