More weird animals today. This time, it's Cameroonian treefrogs who are able to shoot Wolverine-style sharpened bone claws through their fingertips, either to defend against a predator or provide traction on slippery surfaces: "Why some members of this family developed such a dramatic form of defense is still a mystery, though the researchers speculate that because amphibians have a remarkable flair for regeneration, the African frogs may heal up afterward, just like Wolverine."

--Britt Peterson