For the eyes: Place the malt balls cut side down on the work surface. Add a mini chocolate chip to each ball by gluing with a little buttercream as a pupil for each eye. Set aside.
For the legs: Cut each of the green gumdrop fruit slices horizontally into 3 thinner slices. Cut 3 toes into each leg (snip with scissors). Set aside.
For the tongues and flies: Place the red gumdrop fruit slices on the work surface. Cut each horizontally into 3 thinner slices. Cut each slice into a narrow strip to make a tongue. Place a mini chocolate chip at one end of each tongue. Snip tiny wedges of marshmallow with scissors to make little fly wings. Cut the end of each wedge off and glue 1 wedge on each side of the chocolate chip, using the sticky cut side of the marshmallow to adhere.
To assemble: Frost each cupcake with about 2 tablespoons buttercream. Place the green sanding sugar in a small bowl. Invert each cupcake into the sugar and press gently to adhere. Attach the eyes by pressing gently into the frosting. Push the legs and tongue into the edges of the cupcake. Repeat steps for all cupcakes.