Bake cupcakes and allow them to cool completely.
While the cupcakes are baking and cooling, prepare the frosting.
Spread a thin layer icing on top of the cupcake.
Place a truffle in the center and press gently to secure it in place.
Fill a piping bag with green icing and attach the grass tip (Wilton Tip # 233).
Start piping from the bottom of the cupcake and work your way upwards until sides and top are fully covered in "fur." The general motion is to hold your piping bag at a 45 degree angle and then squeeze the bag until icing comes out. Then, pull away gently and let the "shags" fall.
Draw black eyeballs on all the yellow m&m candies with an edible marker.
Stick two m&m candies near the top of the cupcake for the eyes.
Stick long black sprinkles on top of the eyes. These will be the eyebrows. Use tweezers (that you only use for handling food) to make this easier. Instead of sprinkles, you can pipe lines to create an angry furrow.
Stick a single red heart sprinkle on the side of the cupcake.
Use black icing and a small round tip to pipe a dot for the nose in the middle and a wide mouth near the bottom.
Stick a Santa hat topper on top, if you like. Enjoy.