Indoor plumbing is one of the greatest advancements of our civilization, it allows fresh running water and waste disposal at our fingertips. This technology meant huge underground structures had to be excavated, starting with the aqueducts of ancient civilizations to the systems of tunnels and treatment plants we have today. For those of us growing up in the 80’s we caught glimpses of the vast network of underground tunnels beneath the cities as we watched our favorite crime fighting quartet, the Teenage Mutant Ninja Turtles, chase bad guys through the never-ending network of tunnels. This was a dark labyrinthine world, one that got infinitely scarier when Stephen King stuck a clown down there. How many of us experienced our first brush with death and funeral rites standing solemnly around the toilet bowl as our parents said a few words before poor old Goldie the goldfish was flushed into another world? It is no wonder the sewers have been a source of urban legends throughout the ages.

One of the most persistent sewer-based urban legends of our time involves a race of mutant albino alligators living in the sewers of New York City. The stories tell us these poor alligators were bought as babies and carried back to New York as tourist trinkets from Florida. These pets were flushed down the toilet when the novelty wore off and they became too big for their owners to manage. The alligators were said to thrive in the watery underground tunnels, feeding on the millions of rats that lived alongside them as they grew into legend. The lack of sunlight turned them white, a trait they passed on through the generations as they bred and multiplied beneath the bustling city streets.

While these stories have been dismissed as urban legends, and most herpetologists agreed that the New York climate was too cold for alligators to survive, there has been the occasional alligator (or Caiman) that has popped up in New York City. Sadly, these are all believed to be recently displaced animals that probably wouldn’t have survived the winter rather than coming from a lineage of subterranean mythical beasts.

In the Victorian era, the UK had its own version of sewer dwelling monsters: The Black Swine of Hampstead. Legend has it that a pregnant sow fell into the opening of a sewer and into the tunnels beneath the city. There she gave birth, feeding her offspring on the rubbish that was continually washed into the sewers.

There is a strange tale in existence among the shore-workers, of a race of wild hogs inhabiting the sewers in the neighbourhood of Hampstead. The story runs, that a sow in young, by some accident got down the sewer through an opening, and, wandering away from the spot, littered and reared her offspring in the drain, feeding on the offal and garbage washed into it continually. Here, it is alleged, the breed multiplied exceedingly, and have become almost as ferocious as they are numerous.

London Labour and the London Poor Vol. 2, Henry Mayhew

The legend continued to evolve, describing how the swine colony grew. The feral pigs began inbreeding with each other and producing new offspring, each litter more monstrous and deformed than the last. The pigs began feasting on the plague-ridden sewer rats that inhabited the sewer with them, eventually turning on each other when the rat colonies were depleted.

These feral pigs became monstrous cannibals that devoured the weaker offspring, ensuring only the strongest survived to pass on their genes to the next generation; they continued to grow larger, stronger and more ferocious. As London sickened and the plague took hold, corpses began to find their way into the sewers and rumors spread that the swine developed a taste for human flesh. Luckily, for the surviving inhabitants of London at least, these swine remained on the Hampstead side of the river. The strong current of the Fleet ditch kept them at bay and away from the outlets where they could escape from the sewers. Yet, as the swine grew stronger with each generation, there was always the possibility that the next generation of swine would be the ones strong enough to finally cross the canal.

We can find sewer dwelling monsters as far back as there were sewers, even back to the early structures of ancient Rome. In On the Characteristics of Animals, written by Aelian in the 2^nd Century CE, we find another sewer monster – this time a giant octopus:

it swam up through a subterranean sewer that discharged the refuse of the aforesaid city into the sea and emerged in a house on the shore where some Iberian merchants had their cargo, that is, pickled fish from that country in immense jars: it threw its tentacles round the earthenware vessels and with its grip broke them and feasted on the pickled fish. And when the merchants entered and saw the broken pieces, they realised that a large quantity of their cargo had disappeared; and they were amazed and could not guess who had robbed them: they saw that no attempt had been made upon the doors; the roof was undamaged; the walls had not been broken through.

On the Characteristics of Animals, Aelian

The story continued, explaining how the puzzled merchants dispatched a trusted servant to their storehouse the next evening, waiting for the culprit to strike again. The servant was stupefied as he saw the giant tentacles reach through the grates, crushing the giant earthenware vessels with ease. Understanding that those tentacles could crush a man with the same ease, the servant hid until the octopus had finished his feasting. Surviving the night, the man ran back to report the astonishing news. That following evening the merchants gathered a crew of their strongest men, arming them with weapons. As the octopus thief struck, the men attacked, hacking him to death in the tunnels.

As we increasingly move into urban settings, the traditional scary woods are harder to find and are being replaced by other environments. The sewer tunnels running under the cities, disused subway stations and abandoned houses become the places where unknown dangers dwell. Spaces that aren’t filled with the light and movement of everyday life, the places where shadows are concealed within the urban jungles. These are the places our monsters now lurk.