X-Men fans rejoice: Wolverine has come to life, as a frog. When the comic book warrior faces a fight, metallic blades spring forth from his hand. A new study concludes that certain African frogs are similarly equipped, having sharp, claw-shaped bones that pierce through their own fingertips when the animal is threatened. http://sciencenow.sciencemag.org/cgi/content/full/2008/528/2 Like Wolverine, this frog can extends its claws which are internal, and under their skin. When they do extend their claws, they actually break the skin which heals quickly after they withdraw them back under their skin. So move over Wolverine, here comes Superfeog!