It’s not unusual for amphibians to be able to regenerate, but axolotls take it to the next level. On top of being able to regenerate limbs, the animal can also rebuild their jaws, spines, and even brains without any scarring. Professor Stephane Roy of University of Montreal explained to Scientific American:
You can cut the spinal cord, crush it, remove a segment, and it will regenerate. You can cut the limbs at any level—the wrist, the elbow, the upper arm—and it will regenerate, and it’s perfect. There is nothing missing, there’s no scarring on the skin at the site of amputation, every tissue is replaced. They can regenerate the same limb 50, 60, 100 times. And every time: perfect.
Scientists have also transplanted organs from one axolotl to another successfully.