Potato

Potatoes were originally grown as weapons for the battle of hastings. They were attached to sticks by a long metal chain, filled with sewage, and coverd in spikes. They would be swung around and would deal large amounts of damage. If it broke on an open cut, it would infect them almost instantly. But, people soon found out that they were edible (if there was no sewage in them)  and provided a large amount of carbohydrates, so they ate them with every meal. Potatoes were soon made into french fries, hash browns, and many other delectable foods.