Combine softened butter, granulated sugar, and brown sugar in a large bowl. Beat with an electric mixer on medium speed until light and fluffy, about 3 to 5 minutes.
Add eggs one at a time, beating well after each addition. Stir in vanilla extract.
In a separate bowl, whisk together all-purpose flour, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, mixing on low speed just until combined.
Fold in chocolate chips and chopped walnuts (if using) with a spatula.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper or silicone mats. Portion dough into rounded balls about 2 inches apart on the sheets.
Bake for 10 to 12 minutes until edges are golden and centers are slightly soft.
Allow cookies to cool on baking sheet for 5 minutes, then transfer to wire racks to cool completely.
Use red and green icing to pipe werewolf paw prints: large oval for the pad and smaller circles for the toes.
