The Enigmatic Ecosystem of the Abyss

The Abyss in Akihito Tsukushi's Made in Abyss is far more than a vertical dungeon; it is a self-contained world where evolution has taken surreal and often cruel turns. The mysterious force field known as the Curse of the Abyss means that every ascent from its depths carries physiological and psychological tolls, shaping not only the human explorers but the very biology of its inhabitants. Each layer, from the sun-dappled Edge of the Abyss to the lightless Sea of Corpses, hosts a distinct biome. Creatures here are not merely monsters to be slain; they are narrative devices, ecological puzzles, and philosophical mirrors. Understanding them is key to grasping the series’ central themes of sacrifice, curiosity, and the cost of knowledge.

The biodiversity of the Abyss is punctuated by relics of a lost civilization, and many creatures seem engineered or adapted around these ancient artifacts. The interaction between the organic and the mechanical, the natural and the artificial, creates a haunting tapestry that invites viewers and readers to question what it means to be alive. From the benign to the godlike, the creatures define the Abyss as much as the abyssal landscape itself.

Key Principles of Abyssal Fauna

Before diving into individual legends, it’s essential to understand a few recurring traits. First, many creatures possess some form of extrasensory perception, often tied to the Force Field. Second, mimicry and symbiosis are rampant—plants imitate prey, fungi control nervous systems, and predators wear the forms of harmless relics. Third, size and danger increase exponentially with depth. A sixth-layer creature would effortlessly annihilate anything from the upper strata. Lastly, the concept of "Value" permeates the Abyss; many species are sought for their relic-grade organs or unique materials, driving the economy of Orth and the ambitions of Delvers.

The official Made in Abyss wiki catalogues dozens of species, but here we focus on those with legendary status—creatures whose stories intertwine with the protagonists or embody the abyss’s darkest mysteries.

The Red Whistle and First Steps

The Red Whistles are not mythical creatures themselves, but they are the lens through which we first encounter the Abyss’s fauna. As novice Delvers, these young explorers carry simple wooden or tin whistles and rarely surpass the first layer. Their naivety often puts them in low-stakes but instructive contact with creatures like the Shroob, the Tama-chan, and the Silkfang. The legendary aspect here is not the whistle but the ritual of initiation: every veteran Delver was once a Red Whistle, trembling at the sight of a harmless herbivore. This human grounding makes subsequent encounters with true abyssal horrors more impactful.

  • Shroob: Small mushroom-like organisms that emit a faint glow. They are sessile during the day but release spores at night that can induce mild hallucinations if inhaled in concentration. Harmless individually, they form the base of the upper-layer food web.
  • Tama-chan: A spherical, fluffy scavenger that rolls along the forest floor. Its soft exterior belies a surprising speed when startled. Children in Orth sometimes keep them as pets, though this practice is discouraged by the Delver’s Guild.
  • Silkfang: A centipede-like predator that spins adhesive silk. While not lethal to adult humans, a swarm can immobilize an unprepared Red Whistle, teaching a harsh lesson about overconfidence.

The First Layer: Edge of the Abyss

At a depth of 0–450 meters, the first layer is a lush, misty forest cut by vertical shafts. Sunlight still reaches much of the area, allowing for photosynthesis and relatively familiar body plans. However, even here, the Curse is present, causing mild disorientation upon ascent. This zone’s most iconic creature is the Crimson Splitjaw, a massive serpentine predator with a jaw that unhinges laterally. Its appearance in both the anime and manga serves as Riko’s first real brush with death and Reg’s first display of his Incinerator cannon. The Splitjaw’s anatomy is a relic of the Abyss’s warped evolution: its bones are semi-hollow yet incredibly durable, and its blood contains a compound that reacts violently with the Force Field.

The Splitjaw’s legendary status grew after the events at the Seeker Camp. Delvers now trade stories of a particular “white-fanged” variant that haunts the area, though whether it’s a subspecies or a singular survivor of Reg’s attack remains unknown. Researchers from the Made in Abyss anime production notes suggest its design was inspired by deep-sea viperfish and traditional Japanese dragons, blending the familiar with the alien.

The Second Layer: Forest of Temptation

Between 450 and 2,600 meters, the second layer is a dense, upside-down jungle where the canopy hangs below the thin rocky ceiling. The Curse intensifies here, causing nausea, vertigo, and numbness in ascending Delvers. Predators become more specialized, and few are as feared as the Ganja—a term used loosely by Delvers for a family of large, reptilian ambush hunters that can remain motionless for weeks, mimicking rock formations. The most dangerous variant, the Ganja-Tatsu, is said to reach lengths of over fifteen meters and can project its stomach lining outward to entangle prey. Encounters are rarely survived, and carvings in the Seeker Camp memorial wall often bear the Ganja’s silhouette.

Other notable lifeforms include the Inbyoshi, a bioluminescent bird-like creature that navigates the inverted forest with echolocation. Its feathers fetch a high price in Orth, but collecting them legally requires a Black Whistle license. The real danger of the second layer is not a single creature but the ecosystem’s interlocking hostility: corpse-weeping blossoms that attract scavengers, then carnivorous vines that consume them. It is a landscape that weaponizes its own beauty.

Reg: A Legend Forged in Metal and Flesh

Though an artificial being, Reg is arguably the most famous "creature" to emerge from the Abyss. Discovered by Riko in the first layer but clearly originating from much deeper, Reg's mechanical body, retractable arms, and devastating Incinerator cannon defy scientific explanation. His existence is legendary among Delvers: the “Aubade,” a treasure of the netherworld, spoken of in hushed tones at the Guild headquarters. The name “Reg” itself is a remnant of a label on his helmet, though its meaning remains lost.

Reg’s place in abyssal mythology is dual. To the inhabitants of the Narehate village in the sixth layer, he is both savior and destroyer—a figure of prophecy whose arrival heralds change. His energy source is organic, requiring frequent recharges in what appears to be a specialized chamber, suggesting that even the ancient civilization that built him understood the Abyss’s bio-mechanical synergy. The official trailer for the film Dawn of the Deep Soul hints at deeper connections between Reg and the seventh layer’s rumored guardians, though much remains speculation.

The Narehate: The Cursed and the Transformed

No exploration of abyssal legends would be complete without the Narehate—humans who have been irreversibly warped by the Curse. While not a single species, they collectively form a tragic, mythic archetype. The Village of Ilblu in the sixth layer is entirely populated by Narehate, each with a unique form and a unique loss. Their existence blurs the line between human and monster, raising uncomfortable questions about identity and the soul. The Hollow, a more aggressive type of Narehate, roam the deeper layers, attacking anything that moves. Their origin is explored in the manga’s Ganja Suit arc, which details how a colony of settlers fled the surface centuries ago and slowly succumbed to the Curse over generations.

Faputa, the self-proclaimed “Princess of the Narehate,” is the ultimate legend here. She is an immortal being born from the desire of the original Ganja settlers and the accumulated value of the village itself. Her body is composed of countless fused relics, and her role as the “Cradle of Desire” ties her directly to the Abyss’s will. Faputa’s legend is one of revenge and redemption, and her interactions with Reg challenge our understanding of autonomy and love in a world where bodies can be remade.

Other Legendary Fauna of the Deeper Layers

The Orb Piercer

Native to the fourth layer, the Goblet of Giants, the Orb Piercer is a porcupine-like creature whose quills are imbued with a deadly neurotoxin that causes a sense of impending doom before death. It can sense the Force Field and predict a victim’s movements with terrifying accuracy. The Orb Piercer is the central antagonist of the Bondrewd arc, as its quills are necessary for the construction of cartridges used in the Curse-bypassing experiments. Its legendary status is cemented by the death of a major character, and it remains a symbol of the Abyss’s indifferent cruelty.

The Turbinid-Dragon

Rumored to dwell in the sixth layer’s Sea of Corpses, the Turbinid-Dragon is a colossal, serpentine entity that liquefies the dead and drinks them. Delver folklore says that it is the guardian of the gate to the seventh layer, and only by offering a “worthwhile” soul can one pass. Skeletal remains of what might be juvenile Turbinid-Dragons have been found in the fourth layer’s flower fields, but no living specimen has been officially documented. In the guild archives, references are secondhand and often dismissed as hallucination-induced by the Curse. However, the creature’s silhouette appears in ancient murals deep within the Abyss, suggesting that it is no mere myth.

The Gatekeeper

Little is known about the so-called Gatekeeper of the seventh layer, the Maelstrom. References in Bondrewd’s research notes and fragments of Faputa’s memories indicate a being of pure Force Field energy, possibly sentient, that judges any who attempt to descend beyond the Sea of Corpses. Some scholars theorize that the Gatekeeper is the Abyss itself given form, a manifestation of the Curse’s ultimate source. This entity would represent the final legendary creature, the embodiment of all the Abyss’s mysteries concentrated into one wrathful, impartial consciousness.

The Ecosystem’s Role in Narrative and Philosophy

The mythical creatures of Made in Abyss are never mere obstacles; each serves a thematic purpose. The Orb Piercer, for instance, represents the unavoidable sacrifices that come with scientific ambition—a direct critique of Bondrewd’s inhuman methods. The Narehate embody the loss of humanity in the face of obsession, while Reg and Faputa question whether consciousness can exist beyond the body. The Abyss itself operates like a Darwinian engine, rewarding those willing to shed their original form, but at the cost of everything that made them human.

This interplay has drawn academic interest from media psychology, with some analysts at Crunchyroll noting that the series uses monster design to externalize internal trauma. The viewers’ fear of the Abyss is not just of death but of transformation—a far more profound dread. Each creature is a what-if scenario: what if you were trapped forever in a form that no longer recognized its past self?

Practical Implications for Delvers and the Guild

From a survival standpoint, knowledge of these legendary creatures is graded and restricted. The Delver’s Guild in Orth maintains a bestiary that is accessible only to Whistles of corresponding rank. A Moon Whistle cannot legally read about the Orb Piercer’s hunting patterns; a Black Whistle is expected to memorize the Ganja’s nesting seasons. This information asymmetry is a form of protection—too much knowledge can incite reckless ambition, as Ozen the Immovable often warns. The guild’s library, however, is incomplete, and many creatures like the Gatekeeper are known only through oral tradition among White Whistles.

Artifacts harvested from these creatures, such as the Orb Piercer’s quills or the Silkfang’s spinnerets, drive Orth’s economy and fund further expeditions. The line between legend and commodity is thin, and the monetization of abyssal life forms is a recurring ethical tension in the series. The pursuit of these materials often dooms Delvers, turning them into cautionary tales that gradually become legends themselves.

Conclusion: The Living Myth

The Abyss is a world where myths are not merely stories but living, breathing dangers and wonders. From the lowly Shroob to the apocalyptic hints of the Gatekeeper, every creature contributes to the rich, terrifying tapestry that Made in Abyss weaves. They are the guardians of the unknown, the keepers of lost knowledge, and the mirrors in which human characters see their own fragility and ambition reflected. As Riko’s party ventures ever deeper, the legends only grow, promising that the final truth of the Abyss—if it exists—will be guarded by the most unimaginable lifeforms of all. For those who study these myths, whether in Orth’s archives or through Akihito Tsukushi’s pages, the creatures remain an enduring invitation to confront the deepest fears and the highest aspirations of the soul.