Line a baking sheet with parchment paper and place the cookies on top.
In a microwave safe bowl, heat the chocolate chips at 15 second intervals, stirring between until completely melted.
Use the chocolate to "glue" the reindeer features into place on the peanut butter cookie.
Place a dab of chocolate towards the bottom, and add a red M&M for the nose. Place two small dabs just above the nose, and add the candy eyes. Add two dabs of chocolate on either side at the top, and affix the pretzels to form the antlers.
Put the baking sheet in the refrigerator for 30 minutes to allow the chocolate to harden before serving.
Notes
These cookies are best served and stored on a flat surface. The antlers tend to break when put in bags.
If you want to freeze the cookies, lay them flat on a baking tray and then place the tray in the freezer to flash freeze the cookies.
Once the cookies are frozen you can place them in a large freezer safe bag.
They can be stored in the freezer for up to 3 months, however, the pretzels will most likely be soggy when you defrost the cookies. Therefore, I recommend enjoying them fresh within a few days or up to a week of preparing them.