The flesh sewers are home to many creatures. Though much larger than their much more common cousins these evolved parasites still want to try a way to fit inside you. So sewer security is always a top priority
But some still get out into the above ground every so often
There’s a large black market for parasite parts and live specimens that the city is trying to crack down on. In part due to how dangerous it is.
Some more slimey individuals even try to sell tapeworm eggs as miracle weight loss pills. To… disastrous outcomes.