"Pepper" is incapable of existing in our reality on her own. As such, it needs an anchor to keep it here so that it can, well, do stuff. When an individual and the entity form a connection, their desire to have it by their side and the entity's desire to remain there are what allows for it to maintain physical existence.
Should the entity lose the desire to remain in the physical plane, it's host lose their desire to keep it around or it's host expire during a case of anchoring, the entity will simply fade away back into nothingness until otherwise summoned again.
The anchor, to both the advantage and disadvantage of both the entity and the one who summoned it, prevents any form of teleportation. While this keeps the entity tethered to its partner... it also prevents the entity from coming to their side at a moment's notice if they are ever separated and need to be together quickly.
Telepathic communication is also established through the link between the entity and the one who summons it, but the individual currently acting as "Pepper's" anchor is not protected from telepathic assault through this link.
The ritual to summon "Pepper" is rather easy. Just chant its name into a mirror a hundred times and it'll show up, it's as simple as that. Unfortunately... most people don't have the patience for that and that's lead to a lack of business for... quite a long time now. Hopefully, that changes soon.
"Pepper" doesn't have any of the needs that a typical living being would and, as such, can't be bought by any conventional means. Ironically, that makes it a more useful partner than most people. The entity has not come to the world in pursuit of money, fame, power, food or anything like that. Its goals are much simpler.
It simply wishes to exist.
To live and experience and find purpose in an unending, empty existence. And so, when summoned by an individual, its only request is that it is provided with a thrilling existence and experience during its stay in our world. Heroes have used it as a weapon to vanquish evil. Villains have used it as a means to obtain power and defeat their enemies.
Regardless of who or what the entity has fought and stood for, the experience, in itself, was a treasure that kept it coming back to exist as a force for change since the beginning of the universe.
"Pepper's" body is, well, an entire isolated universe compacted down to human size. An infinite universe packed within a few feet. As such, it exists as a chemically and thermally inactive mass of matter that is only really capable of interacting with the world around mechanically.
The isolation of the entity's existence also functions to allow it to touch... anything. As intangible or otherwise "uninteractable" forces confront the dimensional barrier separating the two universes, they collide as though they weren't intangible at all. As such, the entity is capable of interacting with spirits, magical beings, entities existing on higher dimensional planes and, well, individuals claiming intangibility as though they were as physical as anyone else walking around in Earth.
In other words, the entity is less chemically reactive than noble gasses and if three beings with vastly different opinions on what was hot or cold (one with a body temperature of 10,000 degrees, another -68 and a third at regular human body temperature) each of them would consider the entity's body to be neither hot nor cold even if all of them had touched her in the same spot.
It doesn't even understand what the words hot or cold even mean, really.
The entity known as "Pepper" was never born and will never die. The concepts of life and death simply do not apply to it. To properly describe the entity's state of being would be to either say that it currently exists or that it currently does not. There is no other way to properly describe it.
It cannot be killed, only banished.
It does not require nutrients, sleep, energy or any outside resources to remain active, only present. Anything that it might've needed otherwise exists in infinite supply within its own small, endless, paradoxical form.
The eyes, nose, and ears of the entity serve no function other than to provide its summoner some sense of comfort through familiarity. The only real sense provided by "Pepper's" body is a weak sense of touch upon contact with the outside world.
How the entity truly observes the world is currently unknown to everyone including the entity itself. But, through whatever cosmic forces that inform the creature of its spacial and universal surroundings, the entity is able to observe not only everything that any living creatures on the planet can but events occurring lightyears away, in separate dimensions and on the astral and spiritual planes. Surprisingly though, the entity is able to perceive neither forwards nor backward into time.
Apparently, growing up in a space outside of time has left "Pepper" quite dulled to time and rather impatient.
In the most literal sense.
The entity often boasts of being a universal reality warper... but then reveals that it is unable to even turn silver to gold or water to wine and can't cast even the slightest bolt of lighting or ray of light down upon the Earth. Despite these contradictory statements, "Pepper" isn't a liar.
The entity is just referring to itself when it says that.
To an onlooker, "Pepper" merely has complete control over every aspect of its own body. In an instant, the entity can turn its skin to steel or stone and choose to be as frail as cardboard or as sturdy as the core of a star independent of whatever it's currently composed of.
It can alter its mass, weight, shape, size and physical abilities on a whim and is capable of flight by merely deciding to move the components of its form to another location independently of its own physical interactions with the world around it. The only issue that "Pepper" has is changing its color to anything other than white or black.
Kinda hard to do when you don't really have an intimate relationship with the light in this universe, isn't it?