Halloween Themed Frankenstein Monster Matcha Tea Cookies

Soften the butter to the consistency of mayonnaise.
Add sugar and mix well with a whisk, then add the egg yolk.
Sift the matcha and flour together.
Cut the flour mixture into the butter-sugar mix with a spatula.
When it comes together, press down on it hard with the spatula until it forms a ball.
Transfer the dough onto a piece of plastic wrap.
Form the dough into a rectangular stick that's about 17 cm long.
Cover with the plastic wrap and refrigerate for 1 to 2 hours.
Mark the stick of dough in 1 cm increments using a ruler.
Cut through the markings with a knife.
Lay the cookies on a baking sheet, and bake in a preheated 300F/150C oven for 22 minutes.
Cool the cookies.
Chop 2 kinds of chocolate and melt them separately over hot water.
Transfer 2 teaspoons of the milk chocolate and the white chocolate to icing bags.
(see Hints).
Dip each cookie in the milk chocolate.
While the chocolate is still soft, make the fringe using the tip of a toothpick.
This is easier if you hold the cookie with one hand.
Put the chocolate-iced cookies on a piece of kitchen parchment paper.
Cut off the ends of the paper icing tubes with the chocolate in them.
Draw the scar and the forehead crease with milk chocolate, and the whites of the eyes with white chocolate.
Put a little chocolate on the nose area to act as glue, and place an M&M on top.
Make the eyeballs and mouth with the milk chocolate, and the cookie is done.
Make different facial expressions.