Using a standing mixer, combine egg whites, cream of tartar, and powder sugar and mix on medium speed until stiff peaks form - about 7 minutes
Split the icing into 2 bowls
Add a few drops of brown food coloring into one bowl and mix until combined. Add in a few more drops and mix until you get to the shade that you lik.
Using only a few drops of black food coloring, mix until you get a light grey shade.
Scoop icing into their own bags
Using the brown icing, pipe a belt from the top of his left shoulder down to the bottom of his right shoulder
Fill it in and let sit for a few minutes
Using the grey icing, pipe squares on the belt.
Using the brown icing , pipe a line down the center
Using the grey icing, pipe small dots in the space between the squares
Let dry for an hour before enjoying