The coat of a Cornish Rex is extremely fine and sometimes curly, the softest of any cat breed. However, their light coat means that they are best suited for indoor living in warm and dry conditions, they might get hypothermia if they stay outdoors in the winter. Their body temperature is slightly higher than most cats (102 F), and these cats tend to hang around light bulbs, the tops of computer monitors, and other warm places including laps and shoulders. Some Cornish Rexes also have a mild cheesy smell peculiar to the breed; this odour comes from scent glands in the paws.
Often the breed is referred to as the Greyhound of the cats, because of the sleek appearance and the galloping run characteristic of the breed. These cats tend to stay playful and kittenish throughout their long lives. Some Cornish rexes like to play fetch, race other pets, or do acrobatic jumps. The Cornish Rex is an adventurous cat and is very intelligent. It can readily adapt to new situations and will explore wherever it can go, jumping into refrigerators, examining washing machines, etc. Some humans consider its antics to be deliberately mischievous. The Rex is extremely curious, seeks out the company of people and is friendly towards other companion animals. It is a suitable pet for timid children.
Cornish Rex cats come in a wide variety of coat colours and patterns, outlined in the standard: solids, including white, blue and chocolate, tiger-striped red tabbies, bicolor "tuxedo" coat in many colours, "smoke" colours and the elegant colour-point pattern standard in the Siamese breed.
The Cornish Rex is a genetic mutation that originated from a litter of kittens born in the 1950s on a farm in Cornwall, UK; hence the first part of the breed's name. One of the kittens, a cream-colored male named Kallibunker, had an extremely unusual, fine and curly coat; he was the first Cornish Rex. The owner then bred Kallibunker back to his mother to produce 2 other curly-coated kittens. The male, Poldhu, sired a stunning female called Lamorna Cove who was later brought to America and crossed with a Siamese, giving the breed their long whippy tails and big ears.
The Devon Rex looks similar in appearance to the Cornish Rex, but has guard hairs and sheds. The Devon Rex mutation is different than the Cornish Rex mutation in that the Devon has shortened guard hairs, while the Cornish Rex lacks guard hairs altogether. Crosses between Devon and Cornish Rexes are not permitted in pedigrees and matings between them will not produce a cat with short wavy fur. Another hair-deficient breed is the Sphynx cat, which has no hair but may have a very light coat of fuzz.
Using the word "Rex" to imply curly or otherwise unusual fur originates from an occasion when King Albert I of Belgium (1875-1934) entered some curly-haired rabbits in a rabbit show. They did not meet the breed standard, but the show's officials did not wish to risk offending the king by rejecting them. Instead, they accepted them but wrote "Rex" (Latin for "king") beside their names.