Lash

  There is something undeniably horrific and terrifying about a bullwhip. Not a simple flail or cat'o'nine tails have you but a full length, ten foot long strand of braided animal hide.
  It isn't as dangerous as a broad sword or ax that are meant to kill.
  The fearful thing about a bull whip is it isn't meant to kill only cause pain. When the leather strikes the naked flesh it rips the skin as it stops suddenly from the impact. A skillful user knows that the end of the whip is traveling faster then the speed of sound breaking the sound barrier thus causing the cracking sound.
  A tiny sonic boom.
 That is well over seven hundred miles an hour in case you don't know. The leather literally explodes the skin on impact tearing flesh and sending waves of pain deep into the soft tissue around the impact spot. 
  Animals and humans both fear it's kiss.
  The idea of strike after painful strike sends chills down any sane persons mind. It has been used for centuries with little or no modifications. It may very well be the worlds most effective motivation tool ever designed.