 More rarely, yarn may be spun from camel, yak, possum, musk ox, vicuña, cat, dog, wolf, rabbit, or bison hair, and even chinchilla as well as turkey or ostrich feathers.Natural fibers such as these have the advantage of being slightly elastic and very breathable, while trapping a great deal of air, making for some of the warmest fabrics in existence.Other natural fibers that can be used for yarn include linen and cotton.