The mimetidrene (/mɪˈmedɪdriːn/) is a black, eye-covered stranger which, on a superficial level, appears solid in form. Its skin has the appearance of being soft and smooth, and its eye markings glow in dim light. Any touch, however, causes its body to break apart into a dark mist, which feels vaporous to the touch, but leaves no residue behind. The mimetidrene's body is filled with black, brain-like structures (composed of the same non-substance as its surface), although these structures only become visible when the mimetidrene's body is sliced with a clean split, which proves difficult due to this stranger's fragile, vaporous form.
The mimetidrene possesses significant regenerative ability, and displays no difficulty recovering almost instantaneously from minor wounds, such as openings sustained when an individual passes their hand through its body. The rate of healing slows down depending on the number of injuries, however. As such, a single wound regenerates in under a second, whereas two concurrent wounds may each take several seconds to heal. Thus, the more a mimetidrene is damaged, the more harmful each subsequent attack becomes.
The mimetidrene's voice is quiet, nondescript, and sounds more like a digital simulation than an organic human voice.
The mimetidrene appears in a wide range of locations, and prefers quiet places with long halls and dim lighting. Schools during breaks, unused office buildings, and private-access underground roadways are common locations for a mimetidrene infestation. When it first appears, it starts off as a loose, dark cloud of vapor, which coalesces and takes form over several hours. It prefers nocturnal hours, and appears during the day only 18% of the time.
The mimetidrene possesses a routine disposition, and appears unaffected by stimulus in its surroundings. It walks with slow, timid steps in a deliberate path through its environment, a thin, black mist drifting off of its surface during these periods of motion. It stops moving at hourly intervals, and remains stationary for either thirty or sixty seconds. When it stops, its back legs continue to move forward for several steps after its front legs stop, causing its elongated body to temporarily curl up or take on a wavy shape.
The mimetidrene duplicates its body when it reaches a fork in its path, and splits into as many individuals as is necessary to travel down each pathway. When it reaches a T-junction, for example, it splits into two mimetidrene, which emerge from each other with a seamless ease, like a double exposure film. When it reaches a four-way intersection, it splits into three individuals. Upon reaching a dead end, it turns around and continues forward in the opposite direction. The mimetidrene continues to duplicate itself each time it encounters a junction, even if it has already duplicated itself at that junction in the past.
A mimetidrene can only travel for 1,987 feet before it slows down, stops moving and fades away. This distance is reset when the mimetidrene duplicates itself, however. If a mimetidrene has traveled 773 feet before duplicating itself, for example, each duplicate can travel 1,987 feet (and not 1,214 feet) before fading away. Thus, a single mimetidrene can persist for an indefinite period of time, provided its path continues to split apart in periodic intersections.
When a mimetidrene meets another mimetidrene, however, both individuals stop moving and fade away. Thus, mimetidrene infestations in expansive, open environments (such as city streets, or extensive facilities) persist longer than individuals in smaller environments (such as houses or apartments).
The mimetidrene always navigates around sensitive individuals who block its path. Sensitives can block the stranger's movement, however, by standing in front of it with their palms spread open and facing the mimetidrene, and their arms raised at a 25° angle. This action causes the mimetidrene to stop moving, and recite two numbers. The first number corresponds to the number of sensitives killed by strangers within a city since the beginning of the infestation in which the mimetidrene occurs. This is then followed by a second number, which varies between 1-999,999,999, the significance of which remains unclear.
After it recites these numbers (which are always spoken in the most commonly used language within the area), the mimetidrene stands in place until the blocking sensitive moves from their path once more, at which point it continues forward, albeit with a slight limp, which persists as the mimetidrene duplicates itself, and worsens each time the mimetidrene (or any of its duplicated descendants) is stopped by a sensitive in this way.
Otherwise, the mimetidrene does not change its behaviour when attacked or engaged, and can be destroyed with relative ease, and with no deleterious effects to the sensitive.
Although the mimetidrene is non-aggressive and is not physically harmful to people, 0.7% of sensitives experience persistent, intrusive thoughts of specific numbers. Affected individuals find themselves unable to resist the compulsion to count to these numbers, and often do so over and over. This effect persists for two to four weeks following exposure to the mimetidrene. Although temporarily disruptive, this effect rarely causes long-term harm to those sensitives affected.
Due to its duplicating effect, the mimetidrene is, in theory, one of the few immortal strangers. Unless it is able to continually duplicate itself, however, it always dies after walking 1,987 feet, after which point it stops and repeats the number of times it has duplicated itself. Although its voice is normally emotionless and monotonous, a mimetidrene which has never duplicated itself repeats "zero" with a fearful, regretful tone in its voice. After stating this number, it dissipates into a black vapor which leaves a thin stain on the wall around it.