Mutated Kobolds in a Sewer

[nakedonmyfoldin]

I’m planning to run a tribe of Kobolds in the sewers. Basically the city above pays them a meager wage to maintain and repair the sewers, and they get a territory all their own and lots (in their opinion) of shiny gold.

An alchemist/mad wizard type may or may not be illegally disposing of his magical slag in the sewers and I wanted this to manifest in the Kobold in a number of ways. Some Kobolds will see it as a plague sent by Kurtulmak for their weakness and subservience to soft fleshies and maybe others will see it as a gift due to some perceived gain in power.

Boils and burns are obvious.
Extra appendages could be cool.
Wings?
Maybe they could manifest breath weapons?

What are some cool flavorful ways (and not necessary negative) that the magical pollution could influence these Kobolds?

[JellyPooga]

I had a similar idea once (back in 3.5ed), that I never got around to implementing in a game in the end (I still might, though);

The whole tribe of Kobolds got infected with were-lizard lycanthropy (I forget how; probably a curse, but I'd have to dig out my notes), forcing them into semi-exile from the rest of Kobold society (you know, more so than usual). So they moved to the city and got themselves set up with the powers-that-be to regulate the sewers, but also with the local thieves guild as spies, etc.

So yeah; your magical pollution could turn them into shapeshifters. With all the grimy, dirty, dangerous creatures down in the sewers, who's going to pay attention to the lizards or spiders on the wall? When the adventurers turn up, they unexpectedly find their foes strangely prepared for them...

[nakedonmyfoldin]

Cool stuff man. What I like about this idea is the classic divide it can put on the tribe, resulting in some monster factions.

The people who are “afflicted” are shunned by their tribe, but they might feel empowered by these new abilities and may clap back and say “you all are weak for not embracing these gifts”. Bam! Tension and infighting

[patchyman]

I think it is a missed opportunity not to make them tortles...

More seriously, I recommend that you take inspiration from Gremlins 2: the new batch. It had a number of modified gremlins that were memorable and flavourful, such as spider gremlin, bat gremlin, smart gremlin, etc.

[nakedonmyfoldin]

I think the tortle thing is done so much it’s almost expected, so I’ll subvert expectations and do the 3rd most common sewer beast (after were rats)

[MagneticKitty]

Werepiranha. I feel the piranha fits the tiny toothy reptiles.

Or make various templates to apply:
All have a 1d6 plus dex bite with added effect with a dc 13 save
Double their hp and add 2 points to each stat. They count as cr 1.

merkobolds (waterbreathing, swim speed, poison and disease immunity because sewer, walk speed 10, lunging bite: if the kobold moves 10 feet before biting the target makes a str save or be grappled (kobolds have low str so should be easy to break. Is just like a little leech))

Arachnibolds (spider climb, web walk, web attack, poison bite extra 1d4 poison on failed con save, poison immunity)

Kobats (fly 30, echolocation, blindsight, draining bite attack heals half damage dealt on successful bite.)

Kobrats (disease and poison immunity, climb 30, diseased bite con save or poisoned until the end of the kobolds next turn)

https://i.pinimg.com/originals/be/95/56/be95568eef46d39c9170440ba5da79ee.jpg

[nakedonmyfoldin]

Werepiranha. I feel the piranha fits the tiny toothy reptiles.

Or make various templates to apply:
All have a 1d6 plus dex bite with added effect with a dc 13 save
Double their hp and add 2 points to each stat. They count as cr 1.

merkobolds (waterbreathing, swim speed, poison and disease immunity because sewer, walk speed 10, lunging bite: if the kobold moves 10 feet before biting the target makes a str save or be grappled (kobolds have low str so should be easy to break. Is just like a little leech))

Arachnibolds (spider climb, web walk, web attack, poison bite extra 1d4 poison on failed con save, poison immunity)

Kobats (fly 30, echolocation, blindsight, draining bite attack heals half damage dealt on successful bite.)

Kobrats (disease and poison immunity, climb 30, diseased bite con save or poisoned until the end of the kobolds next turn)

https://i.pinimg.com/originals/be/95/56/be95568eef46d39c9170440ba5da79ee.jpg

Woah this is some good stuff, I like the thematic application of random sewer animals.