Cat are the kings and queens of stretches.
Musculature of a cat is more flexible than a dog. The cat’s loose muscles, in combination with its backbone, are probably the main reason for the overall flexibility of the cat and cat balance. A cat can arch its back into an inverted “u” shape, curl up in a circle when taking a nap, or rotate one half of its spine almost 180 degrees relative to the other half when necessary. Source: Cat Health Detective