Winged cats is a term for sightings or descriptions of cats with wing-like appendages. There are three different causes of wing-like appendages. The most common is longhaired cats having matted fur. Felted mats of fur can form along the body and flanks if a longhaired cat is not properly groomed. Less commonly, mats can occur in shorthaired cats if molted fur adheres to growing fur over several seasons. When the cat runs, the mats flap up and down giving the impression of wings. These can be very uncomfortable for the cat and can harbour dirt, feces and parasites. Extensive mats must be shaved or clipped by a veterinarian. This explanation is ultimately untenable as the sole solution to the winged cat phenomenon, for several reasons. Many notable examples of winged cats feature shorthaired specimens. The occurrence of mats in longhaired cats is easily recognisable by experienced cat owners and breeders, but not recognisable to novices. Matted fur is not considered notable and rarely reported, except by those unfamiliar with the condition. Although mats can occur all over a longhaired cat's body, to novice eyes, they are most noticeable on the flanks when the cat is in motion.
The second explanation of reports of winged cats is a skin condition called feline cutaneous asthenia, or FCA, which is related to Ehlers-Danlos Syndrome (elastic skin) in humans. In winged cats that are due to FCA, the wings only occur on the shoulders, haunches, or back. Winged cats that are due to FCA can often actively move their wings, suggesting the presence of neuromuscular tissue within the wings, which is not present within clumps of matted fur alone.
The third explanation is a form of conjoining or extra limbs. These non-functional or poorly functional extra limbs would be fur-covered and might resemble wings, as in one winged cat case recently documented by Dr Karl Shuker, in which the wings were shown to be supernumerary limbs.
There are more than 138 reported sightings of animals claimed to be winged cats, though some of these are clearly nothing more than individuals with clumps of matted fur. There are over 30 documented cases (with physical evidence) and at least 20 photographs and one video. There is at least one stuffed winged cat, but this may be a nineteenth-century fake or "grift". An undated taxidermy specimen in poor condition can be found in a museum in the Niagara Valley. It has bony structures near its shoulder blades covered with flaps of skin. These might be extra limbs.