The Frog That Breaks Its Own Bones To Make Claws

Trichobatrachus robustus, the hairy frog or Wolverine frog of Cameroon, has a defence like no other. When threatened, it contracts a muscle that snaps its toe bones and forces sharp bone claws through the skin. It literally makes its own claws by breaking itself. It also grows hair-like skin filaments to breathe underwater. After the fight, it retracts bones and skin heals. The only vertebrate known to use self-inflicted bone fracture as a weapon.