'Cities in the deep? I've never heard such foolishness. A talking lobster? Rubbish!'



A massive, greenish shelled arthropod which resembles a small-clawed lobster. The eyes on its articulated eyestalks resemble that of octopi. Some are as long as 10' and weigh up to a ton. The Yarnuks encountered by most people seem to be at least as smart as dogs, though the majority of their race are far smarter.


The Yarnuks typically encountered are ‘defective' and have been cast out from their society. True Yarnuk society resides in cities in water with depths in excess of two miles. Masters of elemental magic, they can create new geothermal vents where none exist, or improve the output of existing ones. They farm the creatures that thrive in the sulphurous waters and draw metals and minerals from the water itself.

Rarely, a Yarnuk wizard will develop interest in the surface and will go on an expedition. Yarnuk ships are made from the shells of immense snails that live in the extreme depths.

The exact parameters of these expeditions are highly varied - some simply want to see the wonders of the surface world, some might want to seize treasures - gemstones or other highly durable ones, others seeking adventure or trophies.

While they recognize other sentient life forms, they do not put too much concern into the welfare of others. They may not act out of malice, but will make few efforts to minimize harm either.

Yarnuks are nearly immune to water pressure - only depths in excess of four miles are an issue for them, and they are able to exist on the surface, though they do not enjoy it.

This durability serves them well on the surface, providing metal-like protection from injury. They are also strongly resistant to heat and most toxins.

They are able to operate on the surface for several days before needed immersion in salt water - failure to do so will lead to a rapid decline in their health - including a potentially fatal fungal infection.

Yarnuks communicate with surface dwellers either through gestures, or magic - they have no means to produce vocalizations and communicate with each other either through antenna contact or via limited telepathy. The 'defective' Yarnuks rarely make any attempt to communicate with surface dwellers, although there are always exceptions.

In the world of Decathros, Yarnuks are found in the waters north of Kelevest.


Deep, deep in the waters lies the wreckage of a massive contraption, perhaps the flying machine of some long lost power. Its power supply remains and its exotic energies altered the crustaceans that first colonized the wreck, creating the Yarnuks. The process is far from consistent, and broods of eggs laid right beside this powerplant may have a wide range of outcomes. Occasionally, the energy cause such strange effects that monstrous Yarnuks are created, and need either be slain or driven off by the ‘normal' Yarnuks. Those that are defective - poor intelligence or magic ability - are simply cast out of their society, for while they will not abide the defective, they will not slay their own unless no other options exist.

The defectives have their minds wiped and delivered to much shallower waters well away from their cities, and these are the Yarnuks that surface folks are familiar with.

Campaign Roles:

Major Denizen of the deep

The PCs have obtained some means of exploring the vast depths. The Yarnuks can play the role of general underwater races, ally, enemy or anywhere inbetween.

Deep Knowledge

A Yarnuk wizard is known to the surface wizards as a sage of particular ability in some exotic field. The PCs need to make contact, finding some means to explore the great depths, potentially encountering many hazards on the way.

The Plot

An enemy has learned of the power supply in the deepest ocean, and seeks to retrieve it for some purpose - perhaps to power some super-weapon, or giant golem, or his own iron warship. He may contract the PCs to perform the retrieval, which will pit them against the Yarnuks, who would of course oppose this with all their might. The PCs might be contacted to help prevent this, perhaps by intercepting surface vessels sent to launch the expedition.

Simple Monsters

The Yarnuk are large and dangerous - walrus-sized lobsters, though with relatively small claws. The ‘damaged' ones could easily pose a hazard - either intentionally or through indifference - to coast-dwellers.


? Responses (11)-11

Goto Author

Interesting. I'd have liked to hear more about these cities in the deep, and the society they've created, but I can easily see this appearing in a seagoing Everway adventure.

Goto Author

Sci-fi spell jammers in the deep. I love it. I think we discussed this before in chat: but i like the idea of these beings, and I think it adds different dimension of the setting. By writing from the perspective of one these beings you could use more hard science in you descriptions of life forms and structures. For example you could discuss things in terms of wavelength and ionic attractions ( stuff a being from a crashed spaceship could be aware of), and just having these in the setting expands the setting immensely.

The write up is a little terse. Almost like bullet points. What happened the Valadaar of six or eight years ago that opened up his posts with little in-world first person vignettes?

Goto Author

It reminds me slightly of the Cuthulhu mythology of the deep ones, but has a much more usable origin and some interesting concepts.

I do have to agree with Axle however, in that it feels a bit brief, and I would enjoy reading more about their culture and other unique aspects of their race. (Do they forge metals using geothermal vents?) As for the vignette, that too would be a welcome addition.

Goto Author

Check out the Vorrkush sub

It is another mystical deep dwelling arthropod of Decathros with a Lovecraft vibe.

Goto Author

You can eat that

As long as yarnuk expeditions to the surface are rare, and the only members of their race encountered are the defective cast offs, people are probably going to do with them what they already do with lobsters. I don't see this being a problem, since defective or not, if there are more than enough of them in an area, they are going to breed, and there aren't many ocean creatures in shallow water that are going to be able to kill a one ton lobster with basic intelligence.

I can imagine the horror when a deep snailship surfaces near a coastal village, and the yarnuk explorers discover that the exiles have been captured, and are being bred, and worst of all, they are being eaten. Their boiled shells are polished into jewelry, and the undesirable innards are dumped into the water for scavengers to consume. Juveniles feeding on the discarded viscera of their own kin? Cannibalism, and murder?

This cannot go unchallenged...

Goto Author


Just the right level of detail to be easily adaptable enough to use in a campaign, with a good plot hook and concise campaign notes. Excellent presentation too.

Goto Author

Even though I'm not a gamer, I find myself agreeing more with Kassy on this sub. It is of just the right length for me.

Goto Author

Don't think about it as gaming then. This was part of a world building challenge, and these creatures really add to the world. By having creature in the world a whole new avenue of sci-fi orientated story lines and perspective on story lines is accessible.

Goto Author

Actually, I am aware of the nature of the Decathros challenge but it is true that I did not start reading this sub with the Decathros association in mind. My comment was basically written from my impression that the length of this sub was what Val had intended it to be and the fact that I'm fine with it in this particular instance. But yes, I can understand why others would expect more of this sub starting their reading experience from the Decathros angle. And in general I do think that more content in a sub would be of benefit to it rather than being detriment. In this particular case, I was just judging more on the basis of author positioning, I guess.

Goto Author

This is really good.

Goto Author

Hmm, should put a Yarnuk expansion into the in-work..