This is a simple way to make an unforgettable Halloween Punch.  I like to call it Witches Brew.  I have made this for several kids parties and they all have loved it!

You will need:
A large plastic cauldron or punch bowl
1 Gallon of Green Punch (Kool-aid makes a lime flavor, or Hawaiian Punch also has green - any brand will do)
2 packages lime jello gelatin

What to do in advance:
Chill the punch in the fridge for at least a few hours
Make the Jello according to the directions on the package

What to do at time of serving:
Take a fork and mush the jello into globs
Pour punch into cauldron
Add jello to punch
Enjoy!

Variation:  You can use purple (grape) punch and jello

Tips: 
This punch does not work well in a pitcher - the jello will settle, so it is best served in a bowl with a ladle so it is stirred up.  
Don't add ice, it will dilute the flavor.  If you think the punch will sit long enough to get warm, and you feel you just have to have ice - make ice cubes out of the punch and use them
A lot of the witches cauldrons sold now have a very small hole in the bottom - be sure to double check that yours doesn't by holding it up to a light to see if it shines through.