'Horror frog' breaks own bones to produce claws

""Amphibian horror" isn't a movie genre, but on this evidence perhaps it should be. Harvard biologists have described a bizarre, hairy frog with cat-like extendable claws.

Trichobatrachus robustus actively breaks its own bones to produce claws that puncture their way out of the frog's toe pads, probably when it is threatened."

http://www.newscientist.com/article/dn13991-horror-frog-breaks-own-bones-to-produce-claws.html