Like a surfboard, or a toucan's beak. I assume the poster above imagined the something inside could just be voids, like a tiny aircraft. But yes, some kind of

Like a surfboard, or a toucan's beak. I assume the poster above imagined the something inside could just be voids, like a tiny aircraft. But yes, some kind of low density filler could also add some stability in areas you don't want mass metal but also don't have electronics or battery "cargo".