You need a clear bowl and a rubber glove from the first aid kit.
The day before, pour as much liqueur as possible into the glove and close as airtight as possible with a rubber band. Freeze in a nifty location or, if it`s cold enough, hang outside with your fingers facing down - that`s best.
Peel the lychees and remove the white pulp at one end so that you can see the core a bit: The whole thing should look like an eye. Or just taking the can of lychees is less of a hassle, but it doesn`t look that scary either.
Just before the guests arrive, pour the prosecco into the bowl, add the lychees and carefully free your frozen hand from the rubber glove with scissors. Put your hand in the bowl, it will float on top and melt very slowly, the punch will then turn slightly pink.