Mother Nature Network

Before being fitted with her artificial fin, which her handlers refer to as her “ninja suit," Allison the green sea turtle could only swim around in tight circles because she only had one flipper. Her handlers think it’s likely that she lost her other three flippers to a shark.
 
Her prosthetic fin acts like a rudder and keeps her stable. The turtle has learned how to flap her one good flipper in unique ways to change direction. She enjoys her ninja suit so much that her handlers say she tries to swim away any time they approach her to remove it.
Check out 8 other animals that use prosthetics.