Here's a link to some great food pranks.
We'll be having the colorful cupcakes for dinner (along with sides to be brought out later). Dessert will be ice cream potatoes with faux fishsticks and peas.
I first tried these dinner pranks when G was just about two or three years old. It totally wierded him out. He cried over the cupcakes; and I felt so bad that I tried to let him go straight to dessert, but he wouldn't believe that the potatoes were really icecream.
And I think April Fool's Day is as great an excuse as any to mix up some goop.