The MI5 says this chocolate bar is really a grenade. Made of steel and covered in chocolate, the Nazis designed this during WWII to kill British Royals, who were thought to be chocoholic and stupid. The Royals only had to open these and seven seconds later they will be dead. No bomb ever arrived to Britain, so the Royals remained as chocoholic and stupid as they ever where. [MI5 and Wikidpedia via Spluch]
source:
http://gizmodo.com