You think you know horror? You know nothing.
You might assume – upon glimpsing its ghastly, four-pronged, pharyngeal maw – that the blood worm is a carnivorous animal, and you would be right. But this creature's name actually has nothing to do with its doubtless considerable capacity for bloodletting. The blood worm's name is actually a reference to its color. Its skin is translucent, and so serves as a window to the ruddy, hemoglobin-rich bodily fluids that fill its insides.
It is this same, see-through skin that allows us to watch as its toothy orifice schloops through the distal end of its body and out into the open air.
"I wanted to show friends what blood worms were like but couldn't find a good video on youtube," explains Don Garvey, who captured the footage above. "If anyone is interested," he offers selflessly, "ill make a video of one biting me in the near future."
More on the bloodworm – a creature that is commonly used as fish bait, despite its ability to "eat right through your body, if it wanted to" – in this clip from Dirty Jobs: