Melt the yellow chocolates in a bowl according to package instructions. Stir in the Cheerios, coat completely. Pour onto a wax paper lined baking sheet, separate into little clumps that are small enough to place on top of a marshmallow. Let cool completely.
Melt the black chocolates in a coffee mug according to package instructions. Stick a sucker stick in the bottom of each marshmallow, dip in the black chocolates and tap off any excess. Place a small clump of Cheerios on top of each coated marshmallow. Push the bottom of the sucker sticks into a brick of styrofoam to dry.
Once completely dry decorate with the black gel icing as desired.