So, the cake was a hit! It turned out pretty good...not pro, but good 'nuff. I added a steak knife stuck into the top of the cake, with jelly blood squirting out. That is what everyone loved. (I'll post pix later.) My dau's cat jumped up on the table and licked some of the frosting off the top of the cake while we were having puu puus. That took a little of the charm off of the cake.
Still, everone loved it. The cake was made with Cacao powder, instead of Cocoa powder, which gave it a milder, chocolate flavor. I put a spiced buttercream in between the layers. It was a nice combo. In the end the cake looked heavy and dark, but it was actually very light and fluffy and not too sweet.