Bake cupcakes in Jolly Santa or Christmas Themed Standard Baking Cups and cool completely on Cooling Grid.
Prepare Buttercream Icing recipe. Tint 1 1/2 cups icing with Brown and Red-Red Icing Color to make brown buttercream icing. Lighten a small portion of the brown icing with additional white icing to make light brown buttercream icing. Tint ½ cup icing with Black Icing Color.
Ice cupcakes smooth with brown icing using Spatula.
For muzzle, pipe a quarter-sized ball of light brown icing with Round Decorating Tip 12 on one side of cupcake. Flatten and smooth with finger dipped in cornstarch.
For eyes, pipe whites with white icing and Round Decorating Tip 5. Pipe dots with black icing and Round Decorating Tip 3 for pupils. For nose, pipe ball with black icing and Round Decorating Tip 3 on top edge of muzzle; flatten with finger dipped in cornstarch. For mouth, outline and pipe in with black icing and Round Decorating Tip 3.
For antlers, break pretzel twists and insert ends into top of cupcake.