My son really wanted a Plants vs. Zombies theme for his 6th birthday party. If you're not familiar with the game, Plants vs. Zombies is an addictive game for the PC or most video consoles by Popcap Games where you protect your brains (and house) from zombies by planting a variety of plants (like Pea Shooters, Wall Nuts, Chompers, etc.). It's really fun :)
Since you can't purchase a Plants vs. Zombies cake or cake decorations, I had to get creative. We have a zombie figurine that came with the collector's edition of the game we'd received as a gift. I then bought some gummy brains at the post-Halloween candy clearance and made the "plants" using non-toxic clay. We got a cake from Costco and had them put a large green square on top. I used a toothpick to draw the game squares and placed the brains, plants, and zombies in the squares so it looked like the setup from the game. The cake was a big hit and my son was thrilled.
The Crayola Model Magic brand clay I used was super easy to work with. I'm not very artistic, but the plants turned out pretty cute despite my lack of skill. You could make almost any decorations this way. All you have to do is remove the decorations before serving. They can be tossed or cleaned and saved.
I wouldn't think that using that type of clay would be good to use on a edible cake with frosting. I know I sure wouldn't want to eat it.
I did do some checking before using the clay. It is non-toxic and made from plant-based ingredients. There are no package warnings other than a choking-hazard warning. It was also only on the cake for about 5 minutes. We set it up, put on the candles, then took them off.
You can actually make a home version of Model Magic using baking soda, cornstarch, water, and food coloring for this project if you're concerned.
