For my brother's 40th birthday, the theme was Skull & Cross-Bones. It was difficult to make the cake not look "cartoon-ish" but I succeeded! The cake is yellow cake with homemade buttercream frosting, tinted a cool silvery-purple (Wilton purple with a drop of Wilton black makes a really cool silver color - test it with a small amount of frosting before coloring the whole batch.)
For the skull, I used the "cake pop" recipe. Bake a cake, break it up into pieces, then add one tub of cream cheese frosting to it. Kneed together and you'll have mold-able cake. I used cookie cutters to cut out the mouth and eyes, then balled up little pieces of the mixture to make teeth.
Had I used white cake, I would have been able to leave the skull uncovered as it looked like bone. (Remove any dark pieces of cake before mixing together.) But, I used yellow cake and it just looked dirty. So, I melted white melting chocolate and poured it over the skull. You have to work quickly in smoothing it out as it hardens quickly.
The bandana is made out of Marshmallow fondant, tinted gunmetal gray, and the Boss Hoss logo is made out of Fruit Roll-ups.
The board that the cake sits on is a piece of plywood. I used a dremel tool to bevel out a trench around where the cake would be in the shape of the cross bones. The board is coated with high-heat metal spray paint usually used to refinish grills. It's not food safe, so do not place the cake directly on it, I used a cake board and covered it in glossy black shelf paper. I got the flame duct tape at Michael's.
When the Skull & Crossbones Birthday Cake was ready to be presented, I added Bacardi 151 to the trench and lit it on fire. It was AMAZING! I have it on video, but I'm not sure how to upload the video to this site.