Black Mantis | World Anvil - Isekai Codex

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Black Mantis

Mantis of Káto

Hidden in the darkness lurks a hulking shadow, its black exoskeleton allowing it to blend seamlessly into the inky black of the winding tunnels. Its spindly legs allow it to move silently, a deadly killer ready to strike at the first unsuspecting soul that wanders too deep into Káto. One may expect to find a hulking behemoth of fur or scales waiting for them in the blackness, but few suspect a large insect, one of many apex predators that roam these areas.   Insects are the surface rarely cause fear in those that travel, but in Káto, the mere mention of insects in the darkened tunnels is enough to strike fear into the heart of the most hardened Warrior. Within these tunnels and caverns, one can find the shadowy figure of the Black Mantis waiting around sharp corners or in the smallest of shadows. In complete silence waits a deadly killer, one that can rarely be detected, even with heightened senses.   Black Mantis are very similar to the Praying Mantis found on the surface, with one extreme difference. The Black Mantis of Káto stand between six and eight feet tall, often towering over its prey. Its large size and silent movements make it one of the most deadly predators found within the tunnels and caverns of Káto. Even so, the creatures are hunted for their precious Black Chitin which is a key component of the incredibly strong Black Chitin Armor.

Basic Information


Anatomically, the Black Mantis of Káto varies little from standard praying mantis that are found on the surface. Their large triangular head has a beak-like snout and mandibles that are incredibly strong. Their two compound eyes, three small simple eyes, and a pair of antennae allow the creature to detect fast movement and track its prey.   The two most significant variations are their coloration and their size. Black Mantis range in height from six to 8 feet tall and have a black exoskeleton once they reach adulthood. This allows them to blend into their surroundings and hunt larger creatures, including people that wander into their territory. Along with their mandibles, their spiked grasping forelegs serve as deadly weapons to hold their prey while being devoured.  

Growth Rate & Stages

It is not uncommon to see glimpses of what seems to be a large praying mantis, often green in color, wandering through the shadows in Káto. The Black Mantis begins life as little more than a standard praying mantis, roughly six to eight inches in height and a bright green. Over time and by gorging itself on large amounts of meat and flesh, the mantis will eventually grow to full size, and its exoskeleton will lose the bright colors of adolescence and be replaced by the deep black that allows them to hide in the darkness.  

Dietary Needs & Habits

Insects are rare in Káto, but it is even rarer to find an insect that requires the interesting diet that the Black Mantis do. These creatures are known to have similar dietary needs to Landsharks and other carnivores. A single adult Black Mantis can consume as much as ten pounds of meat and flesh a day, making this creature one of the apex predators of Káto.   Because of its dietary needs, it has been noted that Black Mantis are not picky in terms of where they acquire their food. People and all creatures in Káto can be used as a food source as long as the mantis can trap and hold the creature with their forelegs.
Young Black Mantis
While very young, Black Mantis are usually a bright green, making it harder for them to blend into the darkness of Káto. Even so, these younglings very rarely leave the smaller caves that they have made their homes until their exoskeleton turns to a darker color and they have reached a height to easily tower over their prey.

Additional Information

Perception and Sensory Capabilities

Black Mantis have a variety of abilities that allow them to be deadly hunters. These creatures can avoid all detection, even by creatures that have the heightened vision of Káto. They are able to keep completely silent and still, disappearing into their environment and bypassing the senses of most creatures as long as they do not move.
Hidden Black Mantis
Due to their coloration, Black Mantis are extremely difficult to spot in the dark tunnels of Káto. In extremely rare instances, it is possible to catch one in the light, but only by using magical means.
Scientific Name
Mantidae Káto
Conservation Status
Heavily hunted in most areas due to overpopulation and extreme danger
Geographic Distribution
Related Materials

Black Chitin

The Black Mantis is among the most dangerous stealth-based predators in the upper tunnels of Káto, but their exoskeleton is known for its durable quality and is a sought after material in making armor. It is lightweight, highly resistant to bladed weapons, and does not burn easily. These factors and its natural camouflage properties that persist after the creature's death make it an incredible material for armor and shields. The armor is just as strong as metal if it has been treated properly and lacks the disadvantage of being as noisy as metal scales or rings.   The secondary use of this creature's exoskeleton has been repurposing the spiked arms for use in traps and defensive structures. Many a Gem Dwarf trap has been triggered by trespassers that step on a pressure plate only to have a dozen spiked mantis arms spring from a slot in the wall, seizing and pinning whatever happens to be standing there at the time. The spikes on these arms are long, curved, and grown in a way that leaves wounds that are difficult to heal if one simply rips their flesh away from the restraint.


Author's Notes

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Grandmaster ChroniclesofEvalaw
Olarae & Astaroth Arcaine
5 Jul, 2022 19:24

As someone who used to breed and own ALOT of praying mantises, I automatically love this.

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1 Aug, 2022 14:35

Excellent work! I can imagine the praying mantis’ forelegs reaching out and grabbing me. I really like how the grow from regular praying mantises that continuously grow over time until they’re this monster.

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