Oh these. They're actually born without a face, or much of anything there really, making them look something like a large tape worm. They spend most of their time in the deeper parts of the ocean, but for whatever reason they've been known to show up on shores seemingly dead, but rarely is this so. They react to light (sunlight in this case) by feigning death, as they don't encounter any in their usual dwellings and perceive it as a threat. We call them sleeping bags where I'm from, because they look a lot like a pale sleeping bag floating in the water during the day, but at night (when the sun isn't bothering them) they've been known to smother and swallow any unfortunate person that may be laying by the water and/or kicking/splashing their feet, covering them almost entirely, then quickly re-submerging into the lower depths. This drowns the person within seconds, as the panic sets in and the worm's poison paralyzes them almost instantaneously. Sometimes they have trouble digesting the entirety of the meal and much of the upper body can remain inside of them for weeks, even months. In rare cases, the young worms will actually grow over the heads of the people they've swallowed and part or all of the head becomes meshed within their flesh, and startlingly, becomes part of the worm itself. This is all false of course, but this is the story my brain tells me when I look at it.