Under Yar Tashmak click
Wandering Encounters
1 Sewer Militia
2 Gore Worm Infested Bodies
3

6 Nirlocks AC: 6
Hit Dice: 2
HP: 6

Attacks: 2
Damage: 2d4, 2d4 (Hacker)
Save: F4 (F6 vs Poisons)

Spider hunters wearing masks and googles.

4

10 Smugglers

AC: 4 HD: 3 HP: 12 Armed with axes and wrist crossbows with envenomed tips. Save vs. sleep. They're smuggling gold. Using trained giant spiders as pack animals. Spiders won't attack, but are pretty scary.

5

Loathsome Mass

A Revolting Mess
The mere sight of a Loathsome Mass is enough to elicit a deep sense of revulsion in the viewer, causing them to make a Save or be momentarily debilitated with such a powerful sense of disgust that they spend the next 2d6 minutes wracked with intense nausea, disoriented, distracted, actually vomiting, or seeking to avoid looking upon the horrid thing any further. Those who succeed on their Save can close and hopefully dispatch the lurid, leprous thing.

Atavistic Toxicity
The milky fluids of a Loathsome Mass are poisonous, and will cause those who come into contact with them to regress to a deeply primitive state of consciousness. These fluids are potent toxins and all Saves are at a -2 penalty. Those who succeed are mentally and emotionally regressed to the level of a savage, ancestral being from a much earlier stage of development for only a few minutes. Those who fail their Save regress so deeply that they must make a further Save or suffer a secondary, physical form of regression into a much more primitive life form. In certain instances, this regression can be quite permanent.

 

6 The floor settles (1d4) feet, Save or lose balance. (base 30% chance of outgassing.)
7 (2d4) Toothy Worms are wriggling along the floor in pursuit of something good to eat. Their gurgly-hissing noises are disturbing and resemble the sounds made by gleeful children being drowned--a very unnatural and unsettling sound.
8 Corpse. Weird pustules are distending from the thing's skin like bubbles of foul gas or worse fluids. Jostling the thing will cause these pustules to burst, spattering contagious goo across a 20' radius.
9 (1d100) bats. There are also several buckets, shovels, brooms and scrapers piled-up against the wall from a local guano-collecting crew. The bats seem to be using a broken chimney and three different disused and partly collapsed old conduits as both sub-lairs and access-ways to the surface. All three conduits are partly clogged with rubble and debris, and could be used to travel deeper, should one be careful not to unduly dislodge any of the precariously jammed detritus.
10 Ceiling rats scramble about overhead, occasionally dropping into hoods, backpacks, etc.