To decorate cupcakes, fill one piping bag (no piping tip in the bottom) about half full of green frosting. Fill a separate piping bag (no piping tip in the bottom) about half full of chocolate frosting. Twist the tops of the bags and cut about a half inch off the ends of each filled piping bag. Take a third piping bag and cut the end off and fill with a large piping tip. Place the two frosting filled piping bags side by side in the third piping bag with the tip. Twist off the top of the piping bag. Squeezing the piping bag at the top, pipe frosting onto cupcakes in a circular motion. Top the frosted cupcakes with the remaining mini chocolate chips.