Anything can be an ecosystem, it is just a matter of nutrients and consistency. So often we think that habitats are things that only exist outside our walls, where civilization hasn't fully taken hold. Some folk think we sapient species live completely separate from the natural world, that our lands are omitted from everything else. To them, there is a clear line between what is "nature" and what is "civilization" and once you cross those boundaries, the other ceases to be. But in truth, it is all connected, and our homes are a part of the system like everything else. A city may seem vastly different from any other habitat on the planet, but it is still an ecosystem nonetheless. We are but the fauna running about within, and one of the species that thrives in it. And to the shock of some, there are other creatures that do incredibly well in these man-made habitats, finding living within them just as comfortable as we do.
Sewers and dumps don't seem like much but areas of pure filth, but there is still nutrients to be found. Just because we don't eat the stuff doesn't mean it is useless. Look at the dung beetle, an insect that lives off of fecal matter. While a sewer would be a vile land for us, it would be a paradise to such a coprophage. Things in the wild feed off of waste, it is a natural thing. So when we make areas that are nothing but filth, then some species flock to it, seeing an endless buffet. The Otyugh is one such creature.
When one first sees an Otyugh (probably in illustration over real life), it may be hard to wrap your head around what it actually is. The anatomy seems all over, with arms, legs and heads starting to blur together. Some would claim they are a three-legged species with two tendril arms and a large eye stalk, which is an understandable mistake. The Otyugh is hard to decipher as it moves and feeds, and its anatomy changes depending on the situation. In truth, it is actually a large echinoderm, one that possesses six limbs. Two of these arms are sensory, while the other four are designed for feeding, manipulation and moving. All six have sensory organs for smelling and tasting the world around them, but only two have prominent eyes. These organs are much stronger on these limbs, versus the crude eyes on the others that can only tell between light and dark. All arms work together to help the creature move and feed, though hunting for food isn't exactly a challenge for an Otyugh.
As I made clear, this species is one that feeds entirely on waste, finding poop and filth quite delicious. It isn't just feces, it is anything rotting, foul and discarded that they eat. Their central mouth is a complex arrangement of grinding plates, shredding teeth and potent acid, all designed to consume absolutely everything that gets shoveled in. They are the cleanup crew of the world, like all scavengers, and will erase any detritus or corpse that has been left behind. They are practically immune to poison and disease, devouring plague ridden carcasses without worry. They are essential creatures to areas rife with rot, which is why they have found their way to humanity's sewers.
Otyugh are a species that originally relied on dragons and other megafauna to survive. Their vast amounts of waste gave the Otyugh sustenance, and thus they were commonly found near dragon lairs. Small creatures don't offer enough for such large beasts, but that changed when some species started stockpiling their filth. When the Otyugh caught wind of humans creating places specifically for waste and trash, they were quick to move in. Here was another consistent source of food, in a place that seemed tailor made to them. At first, people were repulsed, but then they realized if they didn't want the Otyugh there, then they would have to go down there and drive them out themselves. Suddenly, no one was complaining anymore.
While most folk don't bother with these creatures, times do come where people do confront them. I know in some big fancy cities, they don't like the image of a giant poop eating seastar dwelling below, so they got the bright idea of getting rid of them. In other cases, their population gets out of control and they start looking for extra sustenance in face of all this competition. Whichever the reason, trying to drive one out or fight it will quickly make you regret your life choices. Otyugh may be sewage suckers, but they can be extremely dangerous. Their tendrils are dexterous and thorny, capable of whipping them with deadly force. Their limbs are many, allowing them to attack from many angles and continue the battle should they lose one or two. The maw in the center of it all is an "everything-grinder," which can reduce an armored warrior to juice if they get too close. On top of all that is the fact that they are dripping with filth and vileness, which can lead to nasty infections or sickness should one be exposed. Sometimes slayers will succeed in killing an Otyugh, only to succumb to a horrible rotting disease weeks later from a mere scratch they had received. In most cases, fighting them is straight up not worth it. It should only be a last resort, for when the Otyugh start spilling out from their sewer homes and begin eating "fresher" things.
To go back to that earlier mistaken description, of a beast with "three legs, two arms and one eye stalk," there is a reason that was a common belief. When Otyugh are feeding, they are laying down in the ocean of filth, positioned like any seastar you would see on the coast. Mouth down, arms out, just enjoying life. When buried in this waste, you can't really see them. Their bodies are colored and designed to fit in with piles of manure and disgust around them (as if anything would want to eat them), and thus folk miss them most of the time. However, when threatened, the Otyugh will rear up to look much larger and expose its pulverizing maw. This is done by using three tendrils for support, like legs. Two feeding limbs are flailed about in a threatening manner, while a sensory tentacle is held high for it to see its attacker. Now that it has made itself obvious and known, people start paying attention. This is why that description became commonplace, as these postures were how folk even got to see them most of the time!
A funny thing to note is that humans are probably way more familiar with the Otyugh than dryads. Honestly, it was a while before I even got to see one myself! This is because dryads collect and compost their waste at home, making sewer systems rare in our towns and cities. Due to large efforts to recycle and reuse, we don't have large areas of the stuff for an Otyugh to settle in. This isn't meant to be a dig at humanity, more just a neat observation. I will say that some dryads made a business of utilizing an Otyugh to rapidly breakdown substances and objects a normal household couldn't properly handle. It is like a rapid transformation of waste into fertilizer, for those who don't want to wait. Bring your junk to these places, let the Otyugh eat it and get its fertile expulsions in return. An odd business, but it seems to be working pretty well! Of course, there are also rumors that some of these establishments earn the real coin from folks who want certain "somethings" to "disappear..."
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While this entry is written by Chlora, it is one that I would say is not canon. Mainly because I know the DnD company is incredibly litigious and not fans of their stuff being used anywhere else. I mainly drew this thing up because I thought it would be fun and the entry was me exploring the "what if" scenario.
But hey! An Otyugh that is an echinoderm! Hmm. Like a big ol seastar! Hmmm! Perhaps like a starfish! HMMMMMM!
