The es (/ɛs/) is a white-bodied, many-legged stranger that possesses no stripes or other patterning, save for a pair of black, circular eye markings. Its body is composed of a putty-like substance, with no internal organs to speak of. When the es moves, it pulls itself forward on its multitude of small legs, which emerge from and recede into its body with each step. Its small toes turn red upon touching the ground, only to fade into white once more by the time each leg recedes.
Although the es' body is soft and malleable, it resists deformation, and is difficult to pull or tear apart. Due to its putty-like flesh, the es' regenerative ability is nearly instantaneous, and it cannot be killed by gunshots, cuts or impacts. It is, however, vulnerable to extreme temperatures. Its body is softened by heat, and temperatures above 120°F dissolve it outright, turning it into a gooey, gelatinous sludge. Cold temperatures, on the other hand, causes the es' body to harden and freeze. A frozen es' body can be shattered by any blunt impact, an action which proves fatal to the stranger.
The es appears in a wide range of locations, with no particular environmental preference. No more than one es occupies a city at a given time, with generation of a single es occurring less than once every 0.28 years.
When the es appears, it fades into view with a dull, flickering shimmer, and looks around with a curious bewilderment, as though displaced from someplace familiar into a strange, new world.
The es' disposition is measured and cautious, and it moves in meandering paths through its territory (which often encompasses the entirety of the city in which it appears). Although it does not engage in any direct actions towards the world around it, it does display curiosity towards its surroundings, and will stop to admire intricate murals, lushly decorated storefronts, and flashing lights.
Because the es' bodily composition is vulnerable to temperatures, it seeks shelter in the cold, and avoids the sun during hot days. It is common to see an es curled up near a radiator or piece of warm machinery during winter, or tucked beneath a shadowy awning during the summer. In the coldest weather, it picks up newspapers, discarded rags, and other scraps of debris, which it presses into its body to create a sort of insulating cocoon. Once these objects are no longer needed, the es shakes them off with a fluid turning motion and retains no dirt or particles upon its flesh, although newspaper or magazine pigment will, on occasion, leave faint lines and brief images upon the es' skin. These images last only several hours before becoming bleached away by the es' ever-white surface.
The es is unable to respond to animals in any way. Even when attacked by hungry dogs or flocks of crows, its behaviour does not deviate from its usual routine, and it continues to display complete ignorance of all animals even as they tear its body to pieces.
The es is capable of generating holographic, ghost-like replicas of human beings, and generates these replicas based on the people that populate the city in which it lives. Each replica imitates a specific person, although the es may create facsimiles of the same person many times over the course of its life.
Under normal circumstances, these imitations are 99.97% accurate in appearance. A healthy es creates one of these holograms every 10-2,785 seconds, and, as such, generates many thousands of these holograms over the course of its life. These replicas display naturalistic standing or sitting poses, and their facial expressions tend to be either neutral, or somewhat happy. These replicas, like the strangers themselves, cannot be seen by non-sensitives, and vanish when touched. The es winces when a nearby replica is destroyed, but otherwise, remains unaffected. Replicas persist until dissipated by outside forces.
Interest in human corpses is brief, but specific, with the es producing three to thirteen duplicates of the corpse (with these copies ranging in appearance from dead to fully alive) in the direct vicinity before it returns to follow its unseen paths once more.
When the es completes a replica, it also creates a second, unseen hologram inside its body. This second replica is always concealed within the es' flesh, and appears for only an instant. This hologram also emits a brief and unsurprised "ah" sound 0.007% of the time, a sound which goes unnoticed, muffled by the es' sludgy body.
The es avoids sensitives, and scurries away from them when noticed by one. If pursuit continues, the es will begin to create holograms of its pursuer, likeness' arms raised in protective gestures, fearful expressions on their faces.
Sensitives who touch an imitation of themselves become overtaken by an intense desire to be inside of the es. This desire may arise instantaneously, or, it may take months, or even years, to take effect. The mesmerized individual has no way of expressing this desire to themselves or others, but instead, develops the innate ability to hone in on the es' location, and abandons everything else in their life in favor of following the es around the city. Once they manage to corner the es, they press their body against the es' side and force themselves inside of the stranger's soft flesh, even as the es squirms and struggles, terrified by this assault. Once inside, the afflicted sensitive quickly suffocates to death, forcing the es to either brutally yank the person from their body, causing massive injuries in the process, or leave the corpse to fester inside of them until the es becomes ill from the decomposition process and dies.
Otherwise, the es is not dangerous, and, when attacked, holds its head in its hands and shakes as though crying in silent sadness, before it gives up and grows still, as though seeing no point in further resistance.
The es is susceptible to human pathogens, and all es eventually die due to human illnesses. A sick es develops a wide range of symptoms, such as reddening or yellowing of the flesh, sluggish movements, and ulcers on its skin. Despite this, the es continues to create replicas, either unfazed by or in defiance of its weakening body. During the first stages of illness, these replicas begin to deviate from normal imitations in small ways, and display angered or saddened faces, or stand in strained, agonized poses. As the es' illness progresses, these replicas take on wounds, such as bleeding eyes or mouths, or pale or mottled skin. Eventually, replicas are created with missing arms, legs, with entire halves of their body absent, or which display otherwise mutated or distorted features and unusual colorations, in addition to any wounded and diseased effects. During the es' final days, it creates only detached limbs or severed heads, and eventually collapses to the ground, splattering before its corpse liquifies completely.