The exterior of all Kigu-Onesies, Kigurumis, Hooded Sweatshirts, and Padded Mitts are made entirely out of anti-pill fleece, a fabric very soft to the touch. There is denim inlaid within the flap where the crotch snaps are on Kigu-Onesies, which gives it extra strength. The denim is not actually visible from the outside.
The crotch snaps in Kigu-Onesies are nickel, and they're buffered enough by the fleece that you don't have to worry about cold metal on your legs when you sit down.
Any poofy bits are stuffed with polyester filling. The polyfill shouldn't need to be restuffed, but we leave a hole open in the tail and/or ears in case it starts to go flat from being sat on too many times.
The collars on padded mitts are strong nylon with durable plastic buckles and small metal D-rings.
Fursuit materials vary by application, but all fur is synthetic.