Addictional informatio n (Wiki):

The munchkin is a relatively new breed created by a mutation that causes achondroplasia, or more likely hypochondroplasia as the skull size is unaffected, resulting in cats with abnormally short legs. However, the shortness of their legs do not seem to interfere with their running and leaping. The breed originated in 1983 when Sandra Hochenedel found an extremely short-legged black cat living under a trailer in Louisiana. This cat, named Blackberry, was pregnant and half of her kittens were born short-legged. One of Blackberry's kittens, a tomcat named Toulouse, became the father of a breeding program that established the breed in North America