It would seem that the Hairy Frog has a unique adaptation. It is able to break its own bones, in its toes, and attacks any who threaten it. A small nod in the bone allows the frog to break it, and thrust the shattered bone through its toe skin, lacerating any who touch it.
Another frog, the otton frog has a similar adaptation, it has a retractable claw that it uses in combat.
This gives a whole new meaning to the Frog Gig!
Note the spike in the tow between the dude's finger and thumb, I missed it at first.