Line a large baking sheet with parchment paper or a silicone baking mat, then place the cookies spaced evenly apart on the baking sheet. Set aside.
Prepare your white "glue" of choice (meaning if you need to melt white chocolate or white candy melts, do so now).
Add the melted candies or chocolate to a piping bag with just a very tiny bit of the corner snipped off, a piping bag fitted with a size 1 or size 2 piping tip, or my favorite option, a small cookie decorating bottle fitted with a size 2 piping tip.
I find it easiest to do one body part at a time, starting with the antlers. Pipe a small amount of "glue" onto the bottom half of the back (preferably the flatter side, if there is one) of a pretzel, then gently press it onto the top of a cookie. When all of the cookies have antlers, move onto the eyes and noses.
Pipe two small dots near the center of each cookie for eyes, and pipe one small dot at the very bottom of each cookie for the nose. Then, gently press one candy eye onto each dot at the center of the cookie and one red candy onto the dot at the bottom of the cookie.
Allow "glue" to set before serving, about 30 minutes. Store leftovers covered at room temperature for 2 weeks.
Notes
Frosting: there are several options for this ingredient. You just want some sort of "glue" that will harden. I suggest my easy royal icing, vanilla buttercream, white chocolate, or white candy melts. Any of these will work perfectly.
Red candies: I used cinnamon hard candies, but you can also use red m&ms or something larger like Sixlets.
Nutrition Disclosure
All nutritional values are approximate and provided to the reader as a courtesy. Changing ingredients and/or quantities will alter the estimated nutritional calculations.