The skulls are available in many stores in Mexico around the time of Día de los Muertos and are also found in other countries where there are sufficient numbers of residents that celebrate the event. You can make them yourself as well. Usually a mold is used and these are commercially available or you can make them freehand, as they were originally made.
Recipe for Sugar Skulls
Sift sugar into a large mixing bowl. In another bowl, mix the egg whites, corn syrup, and vanilla.
Slowly pour the liquid into the powdered sugar. Mix with your hands until a sandy dough forms. Form dough into a ball. At this point, you can continue, or you can refrigerate dough for later use.
Lightly dust surface with cornstarch, as well as your hands. Pinch off a heaping tablespoon of dough, and shape it into a skull. If you're using them, lightly press colored sprinkles into the soft candy. Let the candy dry overnight.
When candy is dry, use the paint brush with food coloring to decorate the skulls. Or you can use frosting (one that will dry hard) with a fine tip to decorate them. Hand them out as is, or wrap in a small cellophane bag tied closed with a small ribbon.
The skulls may not dry completely on a humid or rainy day.
The dough should be the consistency of damp sand, just moist enough to hold together. If the dough is too dry and crumbly, add 1 teaspoon of water at a time to moisten.
If dough is too moist, add sugar 1 tablespoon at a time until dough is the right consistency.
If the candy has trouble drying completely, place in a 125 degree warm oven until dry.