Ural Rex cats are a rare breed of cats that are known for their unique physical characteristics. They have a short, dense coat with a curly, wavy texture, and they come in a variety of colors. Ural Rex cats have large
From Wikipedia
The rex mutation is a genetic variation in mammals that results in soft curly fur. These effects are due to changes in the structure of groups of hairs and cross-section of individual hairs. The rexed coats are unusual but occur in cats, rats, rabbits, horses, and dogs. The mutations, infrequent and spontaneous, occur in a variety of genes and genetic regulatory structures. The diversity of genetic factors results in variable coat thickness/density and fur length. A similar mutation can affect the feathers of birds.