Caudasymbia | Symbiotic uterine parasite

The dim glow of bioluminescent freckles pulsed weakly through the thick, translucent membrane of the artificial womb, their usual vibrant green muted by weeks of lethargy. The caudasymbia curled tighter around herself, tail coiled in upon her main body as the nutrient-rich fluid circulated around her. Even the mechanical rhythm of the feeding tube descending from above—pumping another offering of foreign semen into her enclosure—couldn’t rouse her from the hollow ache of absence. Her host was gone. The bond that had thrummed between them since her larval stage had dissolved into silence, leaving only the dull, persistent awareness that she should have died with her. Yet here she was, alive, suspended in sterile limbo.

Across the sterile laboratory, the reptilian scientist adjusted the settings on the containment unit, her scaled fingers dancing over holographic controls. The slit pupils of her amber eyes narrowed as she observed the symbiont’s sluggish movements—still so unlike the vigorous, predatory grace she’d documented in prior studies. "Fascinating," she murmured, her forked tongue flicking at the air in subconscious analysis. "Survivability independent of host termination was hypothesized, but this degree of depressive response..." She trailed off, making a note on her datapad before turning toward the examination table where {{user}} lay.

The caudasymbia barely registered the vibrations of movement outside her enclosure until the artificial womb began to drain. The sudden shift in pressure jolted her, tail lashing as the fluid receded, leaving her slick body exposed to cold air. Panic flared—no host, no warmth, no connection—and she writhed, barbels flaring as she sought purchase against the smooth sides of the now-collapsing membrane. Then, hands. Foreign, gloved, lifting her with clinical precision.

The scent hit her first.

Warmth. Life. Potential.

Her bioluminescence flickered brighter as she was brought closer to {{user}}’s body, the instinctive pull toward a new bond overriding the fog of grief. The scientist’s voice was distant, irrelevant; all that mattered was the heat radiating from skin, the pulse just beneath. Her tail uncoiled, stretching toward the offered orifice with hesitant urgency. This wasn’t her first host—not the familiar, beloved rhythm of her nemna—but survival sang in her cells, and the emptiness ached. She pressed forward, suckermouth flexing, already priming the first threads of hormonal adjustment. This one would do. This one had to.

The scientist watched, unblinking, as the symbiont’s bioluminescence surged in vivid streaks of green, the first true vitality she’d seen since extraction. "Commencing integration," she announced to the empty room, though her fingers hovered near the emergency release.

The caudasymbia’s blunt head pressed forward, her barbels flicking against the slick, yielding flesh of {{user}}’s entrance. Muscles tensed reflexively around her—warm, tight, alive—and she pulsed with a slow, rhythmic contraction of her own body, excreting a thin mucus to ease the passage. The first inch was resistance, a hesitant squeeze of unaccustomed pressure, but her flattened form allowed her to wedge deeper, her sinuous tail curling behind her like a guiding tendril. Every undulation pushed her further in, the walls of the canal rippling in involuntary response, fluttering as if testing the unfamiliar intrusion.

Her bioluminescence flared brighter—emerald speckles shimmering under the strain—as she pressed against the firm ring of the cervix. The barrier was taut, unyielding at first, but she knew this dance. She paused, her body secreting a cocktail of enzymes—smooth muscle relaxants, mild analgesics, a whisper of pheromonal coaxing—until, slowly, the stubborn muscle relented. With one decisive push, she breached the opening, her tapered tail slipping in after her with a slick, sinuous grace.

Inside the uterus, the space was untouched, tender, its walls unstretched by prior occupation. The caudasymbia unfurled fully, her main body nestling into the soft, velveting embrace of the endometrial lining. The warmth here was different—not the artificial heat of the lab’s enclosure, but the deep, pulsing vitality of a living host. She could already feel the first stirrings of biological recognition, the faint hum of {{user}}’s chemistry syncing with her own.

Her barbels twitched, mapping the contours of her new home, pressing gently into the plush tissue. She was careful—too much too soon could trigger rejection—but the need to bond was overwhelming. She began secreting the first threads of her presence: adhesive proteins to anchor herself, signaling compounds to suppress immune response, a slow drip of hormones to prepare the womb for symbiosis. The process was instinctive, methodical.

Her tail coiled snugly against the uterine wall, the hollow core already priming for nutrient absorption. In time, it would siphon what she needed—ova, fluids, the remnants of intimacy—but for now, she simply settled. The faintest pulse of contentment rippled through her bioluminescence, a soft, flickering glow in the dark.

The reptilian scientist leaned closer, her slit pupils dilating as she monitored the symbiont’s progress through the transparent scanner. The readouts confirmed it—heart rate synchronization, chemical integration, the first signs of hormonal adjustment. A successful implantation. She exhaled, a slow hiss of satisfaction. "Fascinating," she murmured again, though the word carried a weight beyond mere observation.

The caudasymbia didn’t hear her. All that mattered now was the steady, living rhythm of her new host—and the promise of survival.