I wondered if "slender man" was this. An unnaturally tall and thin figure, it doesn't have hands, but some sort of tentacles growing from its back. It doesn't strike at you, you're just likely to feel a sudden, crippling pain if you catch its attention and it comes too close, followed by your certain death. It does not move quickly, but it is relentless - you thought you had outrun it, and then it's suddenly right behind you again.

It occurred to me that this could be how a savanna predator views a human hunter. Our hands wouldn't register as hands (forepaws) for them, they would be some sort of super-flexible grasping thing, like a tentacle. Standing upright we would seem impossibly tall and thin. The animal doesn't understand throwing, let alone guns, all it knows is that getting the attention of this creature is related to sudden pain and death at a distance. Endurance hunting is pure horror - you thought you had outrun it, but there it is again.

I realized a few years ago that cuttlefish were actually little Cthulhus, in behavior, not just form. What does Cthulhu do? His mere presence drives you mad, then he devours you. When cuttlefish hunt, they "flash" their chromatophore-laden skin in writhing patterns that daze or hypnotize the prey, preventing it from escaping or attacking when the cuttlefish moves to devour it.

https://m.youtube.com/watch?v=rbDzVzBsbGM