The Munchkin is a breed of cat characterized by its very short legs, which are caused by genetic mutation. Compared to many other cat breeds, it is a relatively new breed, documented since 1940s and officially recognized in 1991. The Munchkin is considered to be the original breed of dwarf cat.

A dwarf cat is a domestic cat with dwarfism due to rare genetic mutations causing a disproportionate feline body and significant health problems. Unlike undersized cats of normal proportions, dwarf cats suffer from the genetic mutations osteochondrodysplasia and achondroplasia. These genetic disorders of bone and cartilage are typically manifested as abnormal bone shape, poor growth or lack of growth, bowing of the limbs to the side – front legs are more likely to be affected, and spinal malformations.