How can I get gross, bloody stumps in my Halloween punch?
Part of the problem with trying to do this is that you have to select something that's going to stand up to the liquid.  I have a possible solution, but the problem is that the hand itself is going to deteiorate in the process.


Find a glove that's longer, so you have enough "wrist" to work with.
Insert two white plastic rods into the glove as the arm bones;  Trim to length so youcan still seal the glove.
Fill with blood orange juice (not always the easiest thing to come by; I have to go to an italian specialty market that imports it) or cherry jello.
Freeze
Trim the glove to expose the wrist &amp; bones.


If you can't find longer gloves, it might still be possible to make an enclosure to hold the glove upright while it freezeds.  The problem is, you need to put enough pressure on the sides of the glove so that the palm doesn't balloon out too much. It might be easier to freeze the glove normally (with a weight on top to shape the palm), remove the glove, transfer it to a new one, drill to insert the 'bones', then freeze the 'wrist' portion in the new glove.

other notes :


it might be possible to add gelatin to the blood orange juice so it'll last longer; I don't know acidic the liquid can be for gelatin to still set.  (do not use agar; it won't work).
as an alternative to the plastic bones, the only other thing that I can think of (other than using real bone), would be a panna cotta (milk jello) but maybe use coconut milk as it's a brighter white).  But you want the bone to stay solid while the rest of the hand is deteriorating around it.
normally when you do this, the "hand" melts, but the glove still contains the liquid that was in it.  In this case, as the wrist is exposed, the liquid is going to slowly leak out.  For this reason, it might be good to fill the fingers with something solid (or test how quickly jello or similar hold up in liquids over time.