Preheat your oven to 350 degrees and line a cupcake pan with cupcake liners.
In a large mixing bowl, mix together your cake mix, oils, eggs, and water.
Fill each cupcake liner ¾ way with your chocolate batter, bake for 15 minutes, and let cool
Place your decorating tip into the bottom of the bag and cut a ½" tip off the end of the bag so the tip sides halfway through.
Place the bag inside a tall empty cup, fold the edges over the rim of the glass, and fill with chocolate frosting.
Twist the top of the frosting bag so there's no air in the bag, apply pressure onto the bag on frosting to draw a "poo" shape onto the top of the cupcake, going from smaller to larger swirls as you work your way down.
Carefully cut your white melting candy in half and place onto the bottom of the "poo" for the mouth.