Divide frosting in half. Color one half pink (one small drop red food coloring), and color other half gray (5 parts blue, 3 parts red, 1 part yellow). I suggest mixing the food coloring in a separate bowl and then adding it into frosting in tiny amounts until reaching desired shade.
Frost 12 cupcakes with gray frosting, and 12 with pink frosting.
To make pig cupcakes - Using a knife, cut a pink marshmallow diagonally to make two ears. Place on pig. Use a whole pink marshmallow for the nose. Add 2 mini chocolate chip eyes.
To make koala cupcakes -Frost white candy wafers with gray frosting, and place into position as ears. Add two mini chocolate chip eyes and a jelly bean nose.