The flavor of the cake didn't matter so whenever I'm told that, I go with marble. It seems to please EVERYone. Andrew's cake also had chocolate chip buttercream - just for fun. I made a 6-inch and an 8-inch cake. The topper was a toy I found at Toys 'R Us and I think it fit perfectly!
It blended in nicely at its final destination. :)
And most importantly, Andrew seemed pleased.