WaterJet crabs Species in Atocitera | World Anvil
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WaterJet crabs

If you want your insides to stay inside you, you should never underestimate these boulder-looking crabs. One moment sitting in river or water, other you got them in your face and going for your life.
Shell is a nice shield, meat is nice to eat. Or trade if you don't like to live.  
-Comment in catalog page regarding WaterJet crabs.


WaterJet crabs are known for their round, usually mossy, rock-like shells and ability to throw themselves at their prey via a concentrated jet of water.
  Their round shell allows their legs and pincers to be hidden and only revealed after they spring into action.
With 5 pairs of legs, they can quickly move aside to dodge certain kinds of attacks. Thanks to hooks at the end of these legs, they can be used to attach themselves to their targets.
The belly of the WaterJet crab contains four sacks that the crab uses to bloat and inflate to produce jets of water or air. With these jets, the crab can perform a surprise lunge forward.
Most dangerous on them are the pincers made for quickly getting through flesh and damaging whatever is inside their prey. When the crab attacks, its pincer pierces the prey, while the sharp outer part of the pincer cut the wound open. The majority of the crab's pincer's strength goes into the opening.
The mouth of the crab is toothless. The crab uses its sharp pincers to cut or crush the bits into small enough chunks so it can swallow them whole.   There are two variants of the WaterJet crabs when it gets to the elements of the Flow. Breath variant and Charge variant. None of the variants uses its Flow for lethal purposes.
The Charge variant uses its Flow to send electrifying shocks either into the body of water they lie in wait, or to their prey during the attack.
Breath variant usually generates barely visible or light fog around the area they wait in ambush in. Thanks to this Breath fog they are aware of each other as well as any possible prey. The Breath variants most often launch surprise attacks before the prey had a chance to detect them.      


The WaterJet crabs tend to grow indefinitely, but to do so, they need to shed their carapace and shells. Growing new ones require a great amount of calcium which the crab gets from the bones of their prey.
Young crabs have specific growth on the inside of their pincers, which serve to increase the friction when they are grabbing bits to eat. Thanks to this, they can rip out smaller bones from the wounds they open.
Throughout the crab growing, this friction growth disappears, as they become able to eat smaller their prey whole or cut apart the larger ones.
For energy, the meat and fat of the prey serve more than enough.    


WaterJet crabs tend to stay dormant, sitting at their favorite spot in the river or swamp, waiting to ambush anything that would misinterpret them for being a simple boulder in the water.
When the prey gets into range, which is defined by the elemental variant, the crab spring to action.
The swamp variant uses Charge to create a small amount of electricity in the body of water it inhabits. It reacts when the prey gets into contact with the water.
The river variant uses Breath fog to detect prey in a small area around the inhabited river. When the prey gets into range, the crab reacts.   Reaction to prey is always inflating the belly sacks to create a jet of water. This propels the crab in direction of the prey. The crab often lunges forward shell first to be protected from possible counterattacks, resulting impact stuns the surprised prey before the following attack with pincers.
The point of pincers is to pierce the prey and open the wound with the sharp outer edges of the pincers. This creates a large wound which the crab uses to either dig deeper or cause big damage to the insides of the prey.   After the prey is killed, the crabs pack themselves and their four sacks if possible, and then return to their spot to digest. This digestion takes long enough for their shell to start growing moss.
Carcasses next to water full of suspicious boulders are a sign of digesting WaterJet crabs. These pose no threat unless provoked.   The Breath variants residing in a river can occasionally be seen playing from afar. Their playfulness takes the form of many crabs jetting from the river as far as they can. While passing time in this manner, they create sound to possibly lure in curious prey and also check out the range of their lunges.    


WaterJet crabs reside either in the stale body of water or in flowing rivers. Each kind of habitat houses a different variant of the crabs.
Swamps and stale shallow waters house the Charge variant, which generates a small amount of electricity in the stale water.
Rivers and other shallow flowing waters house the Breath variant. The waters housing the Breath variant of WaterJet crabs tends to have a slight amount of fog around them even when the larger surrounding area is perfectly fogless.   Each habitat can sometimes have a carcass of slain prey nearby. Further hinting at the presence of the crabs.    


The WaterJet crabs are spread by eggs.
The river version simply lets the currents carry the eggs away to populate the different parts of the river. Only occasionally do the crabs migrate upstream to their origins.
Swamp variants are much wilder. They lay their eggs, which are comparably sturdier than that of the river variant, and then proceed to hit them with a jet of water to transport them into new places. It is therefore a possibility to be hit with random rock-hard eggs when near stale bodies of water.   In both cases, the newly hatched WaterJet crabs consume the shell of the eggs they hatched from. The baby crabs are born with an already solid shell, but the shell solidifies further a few days after digesting the shell. The baby crabs first start by hunting fish or attacking small animals in groups and proceeds to larger targets as they grow larger.
The size of the WaterJet crab is indicative of how well-fed it is. Crabs of the same age could be of different sizes and if the larger one would consider the smaller one too incapable, they would devour them.    

Relationship to others

Hungry WaterJet crab would not shy from attacking anything regardless of the size difference. The combination of hooks on legs and pincers able to create progressively more open wounds gives them the right tools to dig into the larger targets and cut into vitals.
  Digesting crab is almost equivalent to a regular boulder, and some animals and beasts sometimes use the digesting crabs as a stepping stone to pass rivers.   Thanks to the ambush nature of the crabs, there are fewdangers to them. Among the dangers are animals and beasts with toxic internal organs, which poison the crabs, and water inhabitants able to pass the pincers and mouth to reach their belly and get inside the crab.     

Relationship to Raiders

Crab meat is considered a delicacy, but getting the crabs can be tricky. There is rarely only one crab, and fighting more of them at once requires a skilled group.
One on one combat is fair danger even to some of the seasoned Raiders.   The crab's shells are also sturdy enough to be used as shields with only minor adjustments. This lure was an ill fate to many young Raiders who wanted to get to good gear fast. These heavily underestimated the danger the WaterJet crabs pose and fell to the injuries caused by their merciless pincers.    

Dangers, Risks, Strategy, and Loot

An unexpected hit by lunging WaterJet crab can send a Raider unconscious and vulnerable to its following attacks. When there is any suspicion of the presence of the crabs, traveling in pairs is a minimum.
Depending on the size, the pincer attacks from baby crabs pose danger only if left to continue attacking and then untreated. Larger crabs are able to cause severe damage if they are allowed to land a hit on the body.
A direct hit to an arm or leg could result in amputation on the spot. It is therefore imperative to not let the pincers land a single attack. The best way to deal with a WaterJet crab is to let it lounge forward, dodge aside, and then hit it to its body while it is midair and defenseless.
The crabs tend to look for opportunities to stun their prey with their shell, one way to deal with them is by provoking the crab with a feint attack in order to make them lunge forward and then follow up with a midair counterattack.   After the crab is defeated, its meat can be easily and quickly harvested. Its shell takes some time to get separated from the useless parts of the crab. Once separated, it is sought after material in the creation of shields.
Even though the pincer is dangerous, it is more for a repeated attack, and without the regeneration that it had when attached to the living crab, the pincer goes dull too quickly to be of use.

Details card

Class: Beast
Element: Breath; Charge
Material: Biological; Rock
Region: Rivers; Swamps
Kind of damage: Blunt; Piercing; Slashing; Electrification.
Danger: Challenging; Extreme in higher numbers
Source of raw meat;
Medium grade shield;
Target priority:
Start of Raid: Enough time to stalk and process the whole group.
Middle of Raid: Single Raider has time to process individual.
End of Raid: Combat can take time, best left alone.


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Aug 20, 2022 17:39 by Mardrena Lockehart

Next drawing challenge after completing SWOLEm's Bizarre Adventure, super cute kawaii murder crabs!

Crazy Anime Cat Lady and Gamer Nun, Proud Texan Enjoying Renaissance Faires.
Jul 6, 2023 09:11

The miniature I got from you got 3D printed a few times and is now hiding all over my place!