If you're a prisoner of war and you'd like to freak out the guards, you could start by building a model guillotine out of animal bones. If that isn't enough, it's time to step up your game and use human bones. That's what one French prisoner of war during the Napoleonic Wars did for this model of HMS Victory. You can read more about it from io9's Keith Veronese at the link.
Link | Photo: Heritage Auctions