I know this question may be repetitive but I'm going to ask it anyway before I spend a lot of time trying to do something that's not possible.  I have a character in P6 with very short transmapped hair.  I would like to add a medium length, slender, braided ponytail.  Since this character is for a very active animation sequence, I would like very much have it react naturally without having to keyframe every little movement. 

Now, here's the question:

Can I clothify the ponytail and attach it to the head?  Do you believe it will react naturally if I get the collisions right?

Thanks for any advice you can give.

"slender, braided ponytail" (by which I think you mean what I would call a "plait").

Oh, and just in case you didn't know, "P6 (or P5) hair" is generally understood to mean "Hair-room" hair, not just any hair used in P6. Not trying to criticise, just trying to clear up some possible confusions..

Back to your original query..

Yes, it can be done, but it's not necessarily easy. Depends on the amount of detail you want.

For a fairly distant figure, you can (porbably) just clothify the prop, constrain the verts around the join to the short hair, set it to collide with anything it might hit, set up the anim and let it rip.

For close-ups, if the animation is (as you state) very active that might even work there.
But there's a possibility that the plait (which I expect is fundamentally a tube) might flatten.

There are work-arounds for that, but that's when things get tricky.

I'd say go for it. If you have problems, post here again:-)

Cheers,
Diolma