USS Nimitz (CVN 68) departs from her homeport of Naval Base Kitsap to join Carrier Strike Group 11 in San Diego in preparation for their 2017 deployment. | All Hands Magazine

Unlike the cute, furry hedgehogs that we are familiar with, the anti-submarine weapon known as "hedgehogs" developed during WWII by the Royal Navy of the UK were lethal to the enemy. Prior to the invention of hedgehogs, it was very difficult to destroy enemy submarines, even if they were known to be in the area. See archival footage of hedgehogs in action. | National Museum of the Pacific War