The smoldroni /ˈsmoʊldroʊni/ is a heavy, furnace-like stranger with a core temperature of approximately 2,408°F. Its hollow body is composed of a substance similar to iron, though it cannot be pierced or dented by normal means. This metallic "flesh" displays excellent insulating properties – while its outer surface is smoldering^Ґ to the touch, its hands and feet are not. Despite its durability, however, the stranger possesses no regenerative ability.

The smoldroni appears in a wide range of interior locations.^ђ The presence of iron seems to significantly raise the likelihood of a smoldroni infestation, and it often generates near furnaces, ovens, and large fireplaces. Otherwise, its tendencies lean primarily towards old buildings, empty rooms, and, especially, bare brick walls.

In disposition, the smoldroni is slow and methodical,^ʈ moving in a leaden, lumbering manner, each step accompanied by the screech of twisting metal. It moves at a slow and regular pace, and displays no emotion of any kind as it wanders through blocks of homes, apartments, and shops. Despite its size, the smoldroni prefers small-to-medium-sized rooms over large, open spaces, and eschews crowds.

The smoldroni must consume objects in order to keep its internal temperatures up, and is killed when the fire inside it burns out. Plastics and soft or natural objects (like wood, wax, and cloth) provide better fuel than rocks or glass. There is no preference towards better-burning objects, however; instead, the smoldroni seems to select objects at random. Even a single object, however, can provide enough energy to sustain the smoldroni's life for several days, and death by starvation is not common.

In terms of pursuits, like many strangers, the smoldroni's attention is drawn to the human form. It moves towards and always consumes person-shaped objects^ꝳ within visual range. Some smoldroni also appear able to recognize two-dimensional images of people,^Ӷ with 47% displaying these "flat-abstraction" responses.

When not wandering or eating, the stranger spends its time at rest, its head pointing upward.

Though it does not deliberately cause fires, the smoldroni's passage through tight, dry, or otherwise combustible spaces brings with it the risk from the sparks and embers that flicker from the stranger's mouth and eyes. Should a fire break out near its immediate vicinity, the smoldroni lingers in the flames, a smile upon its face and its body unharmed, even as high temperatures turn its flesh red-hot.^ɺ

The smoldroni remains for some time after the fire has subsided, and once its body cools down, searches for undamaged^Ȿ photographs, jewelry, or other keepsakes, which it crushes beneath its feet, and will not consume as fuel. It is able to tell the difference between a cherished object and one viewed with no attachment, even when not visually apparent via marks or other indicators.

The smoldroni approaches all sensitives it sees, plodding towards them with a weighty inevitability. Once it is close enough, it firmly grabs at its target and drags them forward in an attempt to eat them. It is relentless, and cannot be dissuaded by violence or loud sounds.

The screams of the dying sensitive and the crinkle of their crispening flesh appear to amuse the smoldroni; it keeps its smile for up to four days after the remains cannot be discerned.^Л

The smoldroni can only be dissuaded with water; large quantities prove fatal^ƚ to the stranger.

As the smoldroni ages, its body cools down, and it grows less interested in its surroundings as it starves. Once the spark within it goes out, so too does the smoldroni die, leaving behind its solid "iron" corpse. This corpse can remain for several years, but does eventually rust and break down, persisting only as a pile of black flakes.