kaiten (weapon)
A bizzare weapon in late WWII Japan's collection of such things, the kaiten, or "return to the sky" was a large manned torpedo based of the infamous Type 93 "Long Lance" employed by the Imperial Japanese Navy for suicide attacks, not unlike kamikaze pilots. It was of questionable use and exceptionally dangerous to both those handling them and the pilots; around 200 kaiten trainees, mechanics and hosts (the kaiten were fired from other ships or submarines) were killed while attempting to employ kaitens. Kaitens only sank 3 ships.