Agriltheans are elusive water-dwelling mage demons.

Size ★★★★☆
Phys attack ★★☆☆☆
Magic attack ★★★★★
Recruitment rate ☆☆☆☆☆
Summoner usefulness n/a


Agriltheans are multi-tentacled demons that range from 1.8 to 3m (6’ to 10’) tall. They have some bones but a lot of their skeleton is cartilage and segmented chitinous plates that flex with sinews. They are largely soft-bodied and often thought of as fragile for this reason, but they do not see themselves that way. They would think of bony land-dwellers as fragile because our joints can only bend one way or snap, whereas an agrilthean’s tentacles can entwine any which way without discomfort. They are monocardioids (demons who have a combined heartcore instead of a separate heart and power core). Many agriltheans have some chitinous armour plating.

They are sometimes called ‘arsebrains’ as an insult, but they don’t really understand why it’s meant to be rude. They do have a secondary brain and a more decentralised nervous system than most intelligent beings, and they don’t understand why that’s meant to be a bad thing. (They’ll still be offended if you call them arsebrains because they can tell you’re trying to be rude on purpose, even if they don’t understand why it’s supposed to be rude.)

They can breathe in air, fresh water and salt water. Very young agriltheans find air-breathing a bit difficult, and they shouldn’t be brought out of the water if it can be helped. Some agriltheans live their whole lives and die underwater without ever breaching the surface. They live for around 1,600 Earth years.


These demons are omnivores but can’t digest most land plants – the only plant matter they normally eat is soft weeds. (They can eat grapes, but those are just sugar and water anyway.) They can eat most land meats. Most of their cuisine is raw because they can’t cook underwater, except for boiling (done with geothermal vents or with magic).

Agrilthean poo is hard, gem-like and pretty, and floats to the surface. It washes up on beaches and because of its prettiness is picked up by beachcombers who don’t know what it is. When agriltheans first established contact with surface-dwellers, they were hysterically amused to find that some of the surface-dwellers wore jewellery made from carved agrilthean shit. The value of the ‘jewels’ plummeted overnight and put a few people out of business.


Agriltheans value knowledge and as a species are great cartographers and astronomers (they rise to the surface of the sea to map the stars). They may live in travelling pods or have a territory they defend. Agrilthean culture is quite disparate from ‘mainstream’ (surface-dwelling) demon culture and there is little overlap. Their language and alphabet has no connection to surface-dwellers’. They have two dialects of their spoken language: the normal one they speak underwater, and a truncated/simplified way of speaking that they use when in air. They can make most human speech sounds without great difficulty (they can’t do rolled Rs, as they have a radula instead of a tongue).

They do not wear clothes except sometimes when travelling on land. In this case they may wear e.g. leather sleeves on their leg tentacles so that they don’t have to touch the ground with their bare skin. They can also use their powerful magic to float a little way above the ground and just ‘swim’ through the air. Leg-sleeves are only used for long journeys for which they need to conserve magic.


Agriltheans mostly live in the sunlight and twilight layers of the sea, though there are increasing populations living in fresh water and swamps inland. A few agriltheans live on land permanently because they have a land-dwelling partner (such as Varin with Krog and Melmarus with Serick). While they can live on land indefinitely, they do desire to return to the water sometimes and should be allowed to do so for their mental wellbeing.

Most elusive of all are the abyssal agriltheans. They live in the deep ocean and cannot physically tolerate ascending to the surface (except in a pressurised vessel), so they are rarely seen even by other kinds of agrilthean. Abyssal agriltheans ascending to the limits of their natural tolerance will sometimes meet bathypelagic agriltheans descending to the natural tolerance of theirs. They speak just-about mutually intelligible dialects.

Compatibility with demonologists

It is impossible for a summoner to form a contract with an agrilthean. The demon simply won’t. They don’t hate humans particularly (in fact, they will help drowning humans and are often happy to ferry them across bodies of water if asked nicely), but have no interest in working for us. They might talk to you and trade items with you but can’t be recruited. Of course, a sufficiently powerful summoner could bind an agrilthean to their services by force, but doing that is A Bad Idea.

Magic and combat

Agriltheans do not often engage in physical combat. They could rip your limbs off, or bite you, but can’t really kick or punch (just deliver a tentacle-y slap). They are powerful mages and rely on long-range magical projectiles to kill their opponents before they can close the distance.


The concept of gender does not exist in agrilthean society. These demons are mollusc-like: individuals produce two types of gamete and during reproductive sex can swap both kinds so that both participants can lay eggs. (However, agriltheans cannot self-fertilise.) They do not quite understand the concept of gender as it applies to dyadic species. They can understand why it would be necessary to have some way of telling others ‘I make gamete p and need someone who makes gamete q to reproduce with’ (although that sounds frightfully inconvenient to them), but not everything else it entails. Most of them much prefer to be referred to by non-gendered pronouns so as to opt out of the confusing system.

When reproducing, agriltheans do sometimes argue over which participant has to lay the eggs. Many couples lay some eggs each, in the interests of fairness. Others hold the opinion that the one whose idea it was that they reproduce should be the one to take on the burden of egg production. This can lead to a awkward stalemate in which both partners would like to have children but neither wants to be the first to suggest it.


In the past, agriltheans were mostly r-selectors. They laid large clutches of eggs, and left them to manage by themselves. After a couple of years, any young still alive would be taken in, looked after and raised. As the agriltheans evolved sentience and developed civilisation, they decided it was cruel to bring so many young into existence that were doomed to die, so they switched to being more k-selectors. They still lay large clutches of eggs, but as they lack the resources to raise them all, they set aside the ones they judge to be most hale to be raised, and eat the rest before they have a chance to develop. They lay slightly fewer and bigger eggs than they did at the beginning of their recorded history, demonstrating that they are evolving further down the k-selection path.