I'm sure you're all familiar with the wonderfully repulsive yet perfectly edible kitty litter cake.
With this cake, I've had great success and satisfaction in grossing out un-gross-out-able people, namely my dad and baby brother. However, feeling it to be just a smidge too tame the way it's commonly made, the last time I put one together for a "Guess What You're Eating" themed dinner party, I ramped it up a bit with rice maggots and a raisin fly with onion skin wings.
There, there. Here's a nice pecan tart to settle your tummy.