Of all the denizens of the Amazon basin, there is none more feared than the tiny fish known as the candiru.
The reason for this is the candiru’s supposed habit of entering the human penis, lodging itself in place with sharp barbs, and feasting on it from the inside – a horror story that is enough to keep your legs firmly crossed for days.
So far, so disgusting. But it is not at all clear that any of this is true.
LINK (via: BBC-Earth)