Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups. Make, bake and cool cupcakes as directed on box.
Carefully pull back a small section of paper from each cupcake; insert marshmallow half between paper and cake of each. Frost tops of cupcakes and marshmallows to look like skull shape.
For each skull cake, use 2 mint candies for eyes, 1 chocolate chip, point side down, for nose, and 6 to 8 almonds for teeth. Store loosely covered.