Fanon Pokedex / Shellder

Shellder Line

Morphs [Oak Catalog #]

  • Shellder [#090]
  • Cloyster [#091]

Shellder and Cloyster are both Pokemon encased almost completely in hard shells. Shellder is small, about 0.3 m tall, covered in a flat purple shell. Four small protrusions extend from the shell near the opening. It also has a bright red tongue at least half as long again as the rest of the shell, which is almost always hanging out. The shell is always at least slightly open, but apart from the tongue, only the eyes can be observed, and only then with direct exposure to light.

Cloyster is several times larger, and naturally sits in a more upright position. It is closer to spherical and has many more protrusions coming from the shell, including two which end in large spikes. It does not have Shellder's long tongue hanging out, and the only soft parts of the body visible are now the eyes and mouth. A small white horn extends from above what is visible of the body, which is surrounded by a separate grey inner shell. Cloysters are naturally rare and most commonly seen when Shellder are exposed to a Water Stone.

A rare pigment mutation causes Shellder to have a bright orange shell. The same mutation in Cloyster causes the shell to appear a light blue colour. The mutation does not seem to be heritable, and so it is prized by collectors. Jewellers and artisans also appreciate the rare colouration when they can get access to it.

Notable Biology

The internal structure of Shellder and Cloyster was only determined recently, due to the difficulties involved in examining both organisms. The shells of both organisms are formed from a combination of chitin, protein, and calcium salts, and much of the internal organs lie anchored in pockets within the shell. Any irritating foreign particles that are trapped within the shell get coated with layers of calcium carbonate. Once they form pearls, they are internally moved to sacs near the protrusions and spikes, which then add additional layers of the salt until the pearls form spikes. These spikes can then be launched by the Pokemon as an offensive and defensive mechanism, and both Pokemon have extensive organs revolving around extracting additional salts from their environment for use in this process. The substantially larger Cloyster has many more of these organs, as well as heat-exchanging sacs, as Cloyster develops the Ice type when it evolves. Both Pokemon contain water sacs which allow them to jet underwater, sometimes with surprising speed. They can also physically hop or roll along the ground, either above or under water, though this movement is very slow.

The layered shell of Shellder and especially Cloyster is incredibly durable, and particularly the latter has been compared to precious gemstones in terms of hardness. Even scratching the shell is difficult, and studies have observed that both Pokemon contain enzymes within the shell that rapidly repair scratches and cracks. This is invaluable if the Pokemon fractures its shell as a response to danger (see Hazards below).


Shellder and Cloyster predominantly live underwater, though they can live on land for extended periods of time thanks to their internal water stores. They prefer rocky environments, and while some Shellder are seen on sandy sea floors, no Cloyster is ever seen in the wild away from rocky floor or coral reefs. Temperature does not seem to have a huge influence, with wild colonies being observed in places ranging from the Seafoam Islands to Undella Bay - indeed, the only stable wild Cloyster colonies are in Undella. Because of a need to extract salts to form the spikes they use, Shellder and Cloyster are never found within fresh water.


Both Shellder and Cloyster are carnivorous. Shellder are predominantly ambush predators who usually sit in a spot with their bright red tongue acting out. The tongue acts as a lure, and when something small enough moves towards it or nibbles on it, the Shellder quickly surges forward and snaps down on it. In times of famine, some Shellder will abandon this approach and instead jet around, and try to impale something edible with launched spikes. This behaviour has not been observed to be universal, however.

Cloyster can rarely succeed as an ambush predator, having difficulties hiding compared to the much smaller Shellder and lacking anything that can act as an inviting lure. A Cloyster will instead set up a hunting ground in a rocky area near a more open area of water. When something edible moves close enough to the Cloyster, it will propel itself out of the rocks and attempt to shoot it with spikes. Both species attack prey that are close to themselves in size, and in Cloyster's case, they'll attack even bigger things if they are desperate or aggressive enough.

Both Pokemon also need to eat rocks, minerals, or other substances to increase the rate at which they produce the pearl spikes. They do this by crushing the rock with its shell and then absorbing the salt as normal, though of course it is more concentrated.


Wild Shellder are only a threat if they are particularly hungry or a person antagonizes them somehow, usually by seeking to capture them or accidentally stepping on them if they are in a shallow pool. A Shellder that is stepped on will typically respond by shifting backwards and snapping shut on the offending foot. This can be very painful, and a Shellder so clamping is very difficult to remove by physical force. A Shellder's spikes can cause painful puncture wounds, but they are rarely anything that warrants significant medical care. Cloyster are potentially more dangerous, though at least it's impossible to accidentally step on them. They tend to only attack when hungry or disturbed, and do so almost solely through their spikes. As a Cloyster's spikes are much larger and shot with more force, being injured is a much more serious matter. Some members of each species have been observed to have a phenomenal accuracy with launched spikes, able to strike a target in almost the exact same place even if it moves. Injuries caused by this subspecies of Shellder and Cloyster are much more localised, but also much more severe. This ability is not universal, and there are no obvious differences between the Pokemon with this ability and the Pokemon without.

Finally, a handful of Shellder and Cloyster have been observed, when seriously stressed, to fracture their own shells. This triggers a massive sympathetic response, far beyond an ordinary adrenaline response, and begins launching tiny pieces of their own shell. While smaller, these pieces of shell are far harder and sharper than the spikes they normally use, and tests have shown that a Cloyster under these conditions can puncture even heavy armour used in vehicles designed to travel in mountains and survive the blows of Pokemon like Aggron and Steelix. Its reflexes are sharper and it is capable of moving much faster than it otherwise could. However, the fractured shell is weaker and the stress the technique puts on its body means any injuries suffered by the Pokemon are much more likely to be permanent or fatal. It is unlikely that a human would disturb a Shellder or Cloyster seriously enough to provoke them to use this technique, so it is only recorded to note that if you see a Shellder or Cloyster with a fractured shell, stay away from it and contact your local Pokemon Ranger group. Thanks to the shell's repair mechanism, if the Pokemon is able to rest for a short time, it can mend its shell and return to its normal resting state.

If you are properly prepared, neither Shellder or Cloyster is much of a threat. Like all water Pokemon, electric and grass attacks can repel them, and in the case of Cloyster, fighting and rock attacks also work well. Finally, while the structure of the shells repels physical blows very well, they are essentially worthless against non-contact attacks, which will easily drive them off.

Courting and Childrearing

Both Shellder and Cloyster are fertile, and neither Pokemon courts nor cares for offspring. Males and females release clouds of genetic material during summer, which drift until fertilization occurs. In locations with many Shellder and Cloyster, potentially thousands of offspring can be produced. However, young Shellder are vulnerable during early life, as their shells have not yet fully developed, and so many of them get eaten by other Pokemon.

Social Structure

Shellder ignore any other Shellders nearby. They do not communicate, coordinate, and only compete in the sense that each Shellder tongue in the area decreases each Shellder's chance of eating. Because of this, Shellders tend to end up in small groups based on the amount of food available, as unlucky Shellders go hungry and try to find food elsewhere. The few wild Cloyster that exist rarely come into contact with each other, and are only barely more social than Shellder. If two want to occupy the same piece of rock, they may come into conflict with each other if there is not enough room. Again, if there is not enough food, the Cloyster who is simply not getting as much food moves on of its own will.

In Popular Culture

Beyond one-shot comedic gags in beach settings, Shellder and Cloyster rarely show up as characters in fictional works. However, parts of their body show up a lot more. Both the shells and the pearls, the precursors to the spikes, are highly valued for their beauty, and several priceless artefacts consist wholly or in part of Shellder or Cloyster shell or pearl in real life. This is increased in fiction to the point where anything that is symbolically linked with water has a good chance of being made of Shellder or Cloyster, and a handful of fictional characters have entire suits of heavy armour made of Cloyster shell. Cloyster Plate also regularly occurs as a rare armour in role-playing games.

In a less positive light, Cloyster's vague resemblance to... a certain female organ has been repeatedly pointed out by crude-minded amateur comedians.

Article by Smiggins.