All this is is petri dishes with jello, tapioca pudding and lemon pie filling and some additions to give the look of growing cultures - eeeek!
My boys (ages 7 and 9) would totally dig this but I have to be honest and say that it makes my stomach feel a bit uneasy. Why not tone it down for us queasy folks or kids that may not be into the gross factor. Bright colored jello with gummy worms would work just as well. You'd get a more appetizing looking dessert with a bit of the freak factor with the gummy worms. How about finding some cool candy to throw in.
Lay these out on a table with some plastic tweezers and you have the start of a great Mad Scientist Halloween buffet. Your kids would love it. I also happen to know some adults that would go for some petri perfect dessert.
If you have a local school supply store in your neighborhood you might be able to find some petri dishes there. If not you can always turn to our friend Google and do a search.