I am making a carved 3-D deer head out of Chocolate-WASC. I was considering then using Crusting Chocolate Buttercream under Chocolate Ganash. Then I will cover in fondant! What do you think? I have never done this before, especially on a 3-D cake. Will my ganache break under the fondant?

I know a lot of cakers here have said to use ganach under fondant. IIRC, it holds onto the fondant better than BC does.

I don't know about putting the BC under the ganache, though. Don't recall anyone saying to do that - but then, I could be wrong. It has happened once or twice before.

Ganache under fondant is ideal for 3d cakes but you don't need butter cream as well - use a setting ganache (2:1 ratio of dark chocolate to cream) There are several threads here on using ganache if you haven't used it before.

I was going to do the Choc Buttercream and Ganache since the B-day boy LOVES chocolate...Do you think it's too much?

Pourable ganache over bc is what I'm familiar with. I cannot think of how a spreadable ganache would adhere to a crusting bc. I'm guessing it would just pull off.

Fondant over ganache over bc sounds like overkill to me. Ganache is plenty good on its own or under fondant. It doesn't need bc.

You just need the ganache, plenty chocolatey!