One of my favorites is the Kaiten. This was a human-steered torpedo. This was indeed used, arguably to little avail. Here's some history from a few sources.
warhistoryonline.com/military-…nese-suicide-torpedo.html
en.wikipedia.org/wiki/Kaiten
Some comparisons:
Some documentary stuff. (Uploader edited voice to avoid copyright detection, but the main info is still there.)
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