This may be just totally stupid, but it's something my kids have LOVED (as soon as my husband took them to look at Halloween stuff at the end of August, they're all into pumpkins and bats and stuff).
Anyway, in the Harry Potter books, they drink pumpkin juice, which I gotta tell ya, I don't know that I would enjoy.
Hi-C (yup, the same folks who make the "orange soda" we always got with our McDonald's Happy Meals as kids) has something kind of cool out right now. Since it's now getting popular to try to give out alternatives to candy for Halloween (GOSH I'm glad that trend only started after I was grown up and I have my own kids, whom I have to regulate candy input), Hi-C juice boxes have something called "Frightening Fruit Punch". It comes in packs of 30 at Target for 5 dollars (which is an excellent deal, btw... I know, my kids drink juice boxes like crazy) and on the back they have little Halloween games you can play, and on the front, there are pumpkins and bats. My kids now refer to these things as "pumpkin juice".
Just thought that, if you have little kids or are around little kids, these things would be good to include for a Halloween party.