The luminderi /luːmɪnˈderɪ/ is a glowing stranger with a surface as glassy and translucent as an incandescent lightbulb. Although its movements are fluid, the surface is hard to the touch, and cannot be deformed by outside pressure. Its stripes and eye "markings" vary in opacity, rather than in shade or pigment, although no part is wholly transparent.

The stranger's glow can be attributed to a thick, luminous gas that fills its hollow body cavity. As a by-product of this illumination, the stranger's body radiates a heat of over 120°F, while its much cooler hands, feet, and tail allow it to walk on grass and other flammable surfaces without risk.

Parks and gardens are a common site of a luminderi infestation, although it appears in a wide range of quiet, tranquil settings. It prefers well-maintained flowerbeds, freshly mowed lawns and winding, woodchip-covered paths to the gnarled thickets of wooded lots and urban copses.

It does not generate until late at night, when it flickers into view as a bright flash of light. This cloudy blur dims after several seconds to reveal the luminderi's mature form. Although its surface is almost painfully bright immediately following generation, it fades to its standard level within ten to twenty minutes.

The luminderi's demeanor is calm and peaceful, and its every movement, cautious. It ambles in slow but random paths within its environment, and avoids hard^ɨ surfaces, such as sidewalks or cobblestones.

The stranger appears drawn to flowers, and it spends much of its time yanking them from the earth or plucking them off bushes and trees in idle contentment. After breaking off the blossom, the stranger places it back down upon the stem (if possible) – often picking it up and repositioning it several times until it is "just right."

Plastic, cloth, or paper flowers, however, draw the luminderi's irritation, and it squeezes these imitations in its palm with a tight and frustrated grip before it throws them away with a feigned disgust.

Certain populations of luminderi hold onto 1/34th of flowers and pluck the petals one-by-one.^Ⴙ Individuals exhibiting this behaviour seem to appear more frequently in safer, less violence-prone cities.

Aside from this interest in flowers, the luminderi displays no particular regard for its environment, and while its glowing light often attracts small insects, the luminderi ignores these creatures altogether, even as they crawl upon its lightweight body.

During the day, the nocturnal luminderi stands dormant as long as the sun eclipses its brightness, and only moves again when the sun sets once more.

The luminderi most frequently appears in groups, which do not disperse, nor do they produce wanderers. Although the strain does not, for the most part, display overt communication or gestures, groups seem to work with unspoken coordination to destroy all flowers within an area, and individuals do not compete. Furthermore, luminderi in groups glow more brightly^ჲ than do loners.

Groups tend to ignore other groups that they come across, and display an unsubtle wariness towards lone individuals that attempt to enter into their crowd. When approached by a lone luminderi, the most brightly glowing individual in the group approaches the loner and scratches a small, serial code-like marking on its surface. This action is performed carefully, and only four percent of loners are shattered by the inscription. The marked individual displays no behavioural changes to this scarification, although a non-insignificant decrease in luminosity^ʅ becomes apparent.

The luminderi's presence causes all non-broken lightbulbs to glow, and even unscrewed lightbulbs light up when held near the stranger. The stranger itself regards these objects with some curiosity – it turns its head towards them, approaches, then (if give the chance), etches its mark onto the surface.

In addition to its effect on lightbulbs, the luminderi's presence causes fireflies' bioluminescent cells to multiply at a rapid rate, compressing all other organs to a mortal degree. These insects fall from the ground, twitching with futile scratches, before they dim and go out, their death unnoticed by the stranger itself.

The luminderi is initially shy around sensitives, and moves away from those who move suddenly or make loud sounds. Once it gets used to a sensitive's presence, however, it will approach them, and (when able) place a flower upon their foot. Should the sensitive be in a laying down position, the luminderi covers their body with flowers, stopping only once there are no more blossoms to harvest within an area, or when the figure can no longer be seen.

Statues of prone human beings, corpses, and other human-shaped figures also inevitably eliciting the "flower blanketing" ritual.

When touched by a sensitive, the luminderi dims to a just-perceptible light level, and although its hot surface temperature can make prolonged touch painful,^ನ physical contact otherwise causes no ill effects.

The short-lived luminderi burns out without warning at the end of its life. Other members of its group place flowers around the hollow, unlit corpses of their companions, which remains in place until shattered into thousands of tiny shards. These fragments glimmer as they dissipate, like fragments of ice, and leave nothing behind.