The feredroni /ˈfɛrədroʊni/ is a pale green stranger with a mutable form composed of a foamy sludge. This material is fluid, but leaves behind no wetness when touched, although it bleaches most surfaces^ᶂ that it comes in contact with (a distortion invisible to non-sensitives). Its teeth and claws are solid but flexible, like soft rubber, while its gums are only slightly firmer than the rest of its body. The limbs range between four and ten in number, but can be difficult to count, as legs extend and retract from the body, as well as split apart from each other as the feredroni moves. Though the stranger carries an odor of bleach and other disinfectants, this odor is not strong enough to be unpleasant, and, in fact, resembles the scent of a just-cleaned room.

The feredroni possesses enthusiastic regenerative ability, and small injuries close up within seconds. Although it regrows legs without effort, it cannot reform itself when bi- or trisected, and breaks apart when struck by any firm object, such as a fire hydrant, oxygen tank, or prosthetic leg.

Its voice is garbled. During vocalizations, it splutters and gags indiscernibly, with no consistent linguistic features. When not speaking, the feredroni pants in and out with a manic, strained gasp, like the inhalations of an out-of-breath animal.

The feredroni appears in any artificially sterile environment. Hospitals or medical facilities are the most frequent site of a feredroni infestation, but the strain may also appear in veterinary facilities, morgues, and certain, so-called "higher" academies. The feredroni starts off as a small puddle,^Ƥ from which the head and legs emerge and recede as the pool grows in size. These "basins" form in open spaces or exposed corners in 66% of instances, and in cracks in the wall, inside of cabinets, or in other unusual locations the remainder of the time.

At some point over the course of several days, the puddle splits into three to ten separate and complete feredroni. These emergent entities pull from one another with a splat, and go their separate ways. Even the most restrictive of generation points cause no ill effects to the generating stranger's fluid form,^ƅ which slips out from any restriction like growth of mold and takes solidity as soon as it finds space around it.

The feredroni's form is highly variable, and 45% of individuals display repeating deformities, such as double tongues, or three eye markings, to say nothing of the small, vestigial limbs found on the bottom of many individuals. Atypical individuals suffer no decrease in stability, nor do they display any deviations in behaviour.

Individuals generate with more severe deformities 1% of the time. These feredroni possess one or no eye markings, and can extend only one to three legs at a time. They drag themselves along with weak, hopeless motions before they collapse and degrade, unable to sustain themselves for any longer than seventy or eighty minutes.

The feredroni possesses a mindless, glad disposition. It displays no particular motives or agenda, and wanders through its territory at random, its mouth hanging open and its tongue flopping with each eager stride. As it moves, it leaves its body behind in small fragments and droplets, which fizzle up, evaporate, and discolor the floor beneath them. This dripping causes only negligible loss of form, and any decrease in mass is regained during the stranger's brief, but frequent moments of inactivity.^ʋ

When the feredroni does interact with the world around it, it does so by biting, chewing, and licking whatever knee to ankle-height-objects^ʆ catch its fickle interest. Despite its frenzied gnawing, it rarely leaves puncture marks behind, as its jaws possess minimal biting strength, and its teeth are too rubbery to pierce all but tissue paper.

Medicine bottles and pills are of particular interest to the feredroni, which it consumes with vacuous delight. Though its body retains small objects,^ƀ larger items^ƞ fall immediately through its soft underbelly to the floor below – eliciting a sputter of surprise from the stranger. Successfully devoured objects dissolve over a period of several days, staining, for a day, the feredroni's flesh, before returning to seafoam uniformity.

The feredroni has a grouping tendency, and when two or more feredroni meet, it is common practice for them to join their bodies together to form larger conglomerates. These multi-headed fusions move with staggering, unsteady steps, but do not display any decreased stability or other negative side-effects. After a sufficient amount of time spent joined (which can range from minutes to days), conglomerates split apart again, each individual continuing on its way, no worse for wear.

The feredroni's reaction towards sensitives varies based on size. Small feredroni are more skittish, and avoid sensitives, whereas larger feredroni (as well as conglomerated individuals) approach with happy excitement. While individual feredroni are typically non-violent, larger conglomerates engage in pursuit – sometimes, to a ferocious degree. Although the claws and teeth are too soft to pierce skin, the stranger's foamy flesh acts as an itching, burning irritant upon bare skin.

The feredroni exerts a subtle but strong influence on sensitives, with its presence destroying bacteria. As long as a sensitive is able to avoid physical contact, a short encounter with the stranger tends to be beneficial, with only minimal side effects as the feredroni's antibacterial properties destroy many harmful^Ꮼ bacteria, clearing up even severe surface infections.

Prolonged contact, however, proves deleterious, as the feredroni destroys the numerous beneficial bacteria inside the human body, as well. Victims of such effects become vulnerable to pathogens, lose the ability to digest food, and experience numerous infections, among other symptoms. The rate of this effect varies depending on the size of the feredroni. The smallest feredroni take hours to have any noticeable effect, while encounters with large conglomerates can have fatal consequences after only a few minutes.

The feredroni is drawn to human corpses. Upon finding one, it settles on top and remains there for a long period, a smile on its face and its legs retracted inside its body. As it fades the corpse's skin and muscles, it also slows its rot, leaving the body with its characteristic "waxy-doll" appearance. Once the feredroni is ready to move on, it extends its limbs from its flesh, and continues on its way.

As the feredroni reaches the end of its lifespan, its behaviour becomes more calm and reticent, with only occasional erraticisms, such pacing, repetitive jaw-smacking, and tonguing of its eyes and age-loosened teeth. It dies by pressing forward and into a solid surface, as though walking through some unseen entranceway. It leaves no residue behind, save for a discolored stain on certain materials.

Other feredroni approach and often try to 'merge' with the stain left behind by their now absent companion, an action which causes them no harm, but which does provoke a frustrated response when they are unable to move forward. Otherwise, the stain evaporates completely within 12-31 hours, after which point, all other discoloration caused by the feredroni over the course of its life returns to vibrancy, as well.^ƻ