Terrifying Frog Breaks Its Own Bones to Produce Claws When Threatened
Trichobatrachus robustus is the Wolverine of the amphibian world. You'll know when you've crossed the line because he'll gladly break his own bones to produce weapons to break yours. New Scientist...
https://www.neatorama.com/2013/03/28/Terrifying-Frog-Breaks-Its-Own-Bones-to-Produce-Claws-When-Threatened/