Great, mysterious chambers hidden deep in the earth beneath that enigmatic city of Stoneholt!
The city of Stoneholt is generally considered one of the Wonders of the World, but it conceals a second wonder - a labyrinth of massive sewers and storm drains greater then anything man has built.
The PCs are exploring the catacombs beneath a Colosseum-in-Rome type of structure, when they come across a foul-smelling, stagnant, ankle-deep with algae, public mass latrine. Countless urinals of marble, line this rather large chamber equally crafted of marble. Whatever system of plumbing once worked here, has not in many years. Old graffiti lines the stained,dirty walls, prominently bolded are such intellectual poetic musings as, "Urine For It Now", "I Pee Therefore It Comes" and "Now Urine Trouble".
A few moments after the PCs get to take in this unpleasant location, they hear the low rumbling of ancient plumbing and rather large Urine Elemental rises like a great, wet, wave of filth to attack them. The creature reeks and exudes noxious debilitating fumes, while its liquid strikes burn flesh like acid.