New PoH:

I've not been up to the new PoH yet, but from what I've read the tiny hand sits in room before the room where the Maestro spawns.  No confirmation on if killing the small hand spawns the bigger hand anymore, but now you do not need to kill the new uber Maestro to get the epic drop.

Old PoH:

After you take down the Maestro of Rancor in Plane of Hate, this little tiny hand will spawn where he died.  It cons green, but takes a while to kill.  Now once this hand dies, a much larger nastier hand named 'a very unpleasant hand' will spawn.  That hand is a biotch.  So kill both these hands and from all the info I can find, you can get the epic piece off of either the little wussy hand or this big naughty hand.  Personally, I've only seen it drop from the little hand, so I know what story I'm sticking to.  Or course, all this info could become pointless considering the upcoming PoH changes and the newer uber Maestro is supposedly gonna require 3 groups of 65 to take him down or something, and the epic piece would be moved to a different mob rather than this series of mobs.  We shall see.