Place cookie dough in a medium mixing bowl; stir in drops of green food coloring until desired shade of green is reached. Roll cookies into even portions and freeze 30 minutes. 

Preheat oven to 350°.

Arrange the chilled dough portions at least 2 inches apart on parchment paper-lined baking sheets. Bake at 350° for 6 minutes. Remove cookies from oven; carefully sprinkle chocolate sprinkles at the top of each cookie to create Frankenstein’s “hair.” Return cookies to oven, rotating the baking sheets as you do. Bake for another 7-9 minutes or until cookies begins to set around the edges. 

Remove from oven; immediately place 2 candy eyes and 2 pieces of candy corn on each cookie for Frankenstein’s “eyeballs” and “bolts” while cookies are still warm. Allow to cookies to cool on the baking sheets for 5 minutes; transfer to wire racks to cool completely. 

When cookies are completely cool, draw a mouth on each cookie and finish decorating as desired using the black icing pen.