Shadow people.
Usually small, human figures (sometimes tall with a top hat) that are completely devoid of detail and look black. Often, they are seen out of the corner of one's eye. The person turns their head to look at it straight on and it disappears.
When they know they are seen, they leave, either run off or simply vanish. They often come with feelings of dread.
They do not necessarily show up in haunted locations, sometimes in modern homes, often in parks and cemeteries and outdoors. So, what are they?
Because of their "magical" qualities, most folks assume they are a form of ghost, perhaps something evil, as they have no details and devoid of light.
I will share my own hypothesis and it may make sense to many -
Let's say you are spying on someone. You hide behind the corner of a building and peer out now and then to see what progress the person has made. What you don't think about is the fact that the sun is casting your shadow on the sidewalk and the person knows you're hiding there because your 2-dimensional shadow gives you away.
Your shadow is devoid of detail because it's simply the result of the sunlight hitting you and creating a you-shaped shadow on the ground where the sunlight didn't reach.
Let's take this to another level. There is a higher dimensional being. Let's call him "Tesseract." His give-away shadow would be in 3-dimensional form.
Tesseract thinks he's just enjoying a walk through the park when someone sees his shadow and realizes he's there. The shadow isn't even the source, simply a reflection of it. Imagine what Tesseract himself is like?
If the person on the street chased your shadow, they might get near you, but they are missing the source of the shadow - you.
Once realizing they are seen, shadow people disappear. This featureless dark figure isn't even the culprit, it's just a reflection of them.
The bigger question is what casts their 3-dimensional shadow into our world? It must be intermittent conditions or we would see them all the time.
Is it evil? No more than your shadow is evil. mBut, whatever energy source casts a 3-dimensional shadow likely creates a sensation in our bodies. We feel a sense of dread because of the energy put off by the source of the shsdow. Our bodies might interpret their presence as fight of flight mode.
Hopefully, this Carl Sagan description of a higher dimension helps our understanding of relationships with other dimensions.
I can't help thinking that a photo of yourself is a 2-dimensional image of yourself, showing your face, in a fraction of a second. It can't think, has no perception of depth or awareness, is only a visual facsimile. But, you add one dimension, and you get the biological, living, thinking, moving being.
So, what would adding another dimension do? Well, as the photo of us had no brain to think or perceive the next dimension that was occurring all around it, we cannot perceive the next level up, not intellectually or biologically. It would likely take on energy, frequencies, vibrations and intelligence that is omnipotent. It would be us shed of physicality. In other words, something rather heaven-like, if not heaven itself.
After all, the photo was a facsimile of us and perhaps we are a 3-dimensional facsimile of the higher self - the soul?
Now, soak that in and contemplate this concept. i don't expect anyone to just accept my conclusion, but if it ignites your imagination, run with it. I'd suggeset studying cases of shadow people encounters and higher dimension concepts.
It is such an honor to have intelligent and inquisitive readers. Keep doing what you're doing. You make me proud to know you!