Wipppah!

[TrevoriuS]

What's with the sliding back leg? I can image a sliding leg only if it is in reality lifted a very slight bit from the ground, enough to decrease it's weight by so much the slide is not obstructed by friction, and that only if the leg is not stood upon. In this case the other leg is floating mid-air. Making a slide impossible

[dock]

This looks great, but it doesn't seem to be a 'whip' necessarily. It's more like a bendy piece of rubber or a chain perhaps. I love the motion blur though.

[Emtch]

This doesn't look like a whipping motion. Your animation looks like someone using a sword, a whip is used in a completely different way. When whipping, you should pull back before the whip is straighted out, to give it that supersonic whipping hit.