I had hoped to make a garbage cake, but the recipe I wanted to use needed Oreos, and the kids had eaten them all.
So then I tried for a grass with worms cake, but when I mixed the green and the blue frosting powder, it came out a bit more mucky. So I crumbled a bit of the chocolate cake over the frosting and added (halal- so no pig) gummi worms and went as a garbage-type of cake.
The kids love it. Although T1 wanted more frosting and T2 scraped the frosting off!