Caltrop

A caltrop is an area denial weapon made of several sharp spikes arranged so that one point always faces upward no matter how the device lands, historically scattered on the ground to injure the feet of horses, war elephants, and camels, or to puncture the tires of modern vehicles. The name comes from the Old English word for heel-trap and the Latin tribulus, and the Roman military writer Vegetius described Roman soldiers strewing caltrops across a battlefield to defend against scythed chariots and cavalry. Many cultures independently developed similar devices, including the Chinese jili and the Japanese makibishi, and modern militaries have continued to use caltrops and caltrop-like munitions, including aerial versions dropped by Germany in the Second World War and devices deployed by drones during the Russian invasion of Ukraine to disable vehicle tires.