You can use melted chocolate or pipe your own fav buttercream. This time I use store bought frosting such as Betty Crocker, due to the the filling of the Twinkies itself - which tastes like canned frosting.
Step 1: Method
Black food color, such as Wilton
Take out twinkies from its wrapper. Tint some of the canned frosting with black food color - gel. Scoop frosting into a ziplock bag and snip the corner.
Start pipping mummy style as shown. Then fill up with white frosting. You can make it neater with either a pin or a pastry brush.
Don't forget to pipe the eyes!