Prompt Title: Undercity RPG Encounters.

Encounter: "The Mutant Settlement"

As the adventurers make their way through the dark and murky sewers of Middenhiem, they stumble upon a settlement of mutants. The mutants are a strange and terrifying sight, with twisted and grotesque features. They seem to be worshipping a dark god and are cannibals, with the remains of their previous victims strewn about the settlement. The adventurers will have to use all their skills and wits to navigate this dangerous encounter.

NPC Mutants and their Mutations:

1. Grokk - Grokk has massive, muscular arms that end in sharp claws, making him a formidable fighter.

2. Skreech - Skreech has razor-sharp teeth and a long, pointed tongue that he uses to lash out at his enemies.

3. Maw - Maw has a massive, gaping mouth filled with rows of sharp teeth that he uses to devour his prey.

4. Shriek - Shriek's voice is so loud and piercing that it can cause physical harm to those around him.

5. Rippa - Rippa has long, razor-sharp claws on his feet that allow him to climb walls and ceilings with ease.

6. Gnarl - Gnarl's body is covered in thick, matted fur that provides him with excellent insulation and protection.

7. Slurk - Slurk has a long, prehensile tongue that he uses to snatch his prey from a distance.

8. Twitch - Twitch has the ability to move incredibly fast, allowing him to dodge attacks and strike with lightning speed.

9. Hiss - Hiss has a long, snake-like tail that he uses to wrap around his enemies and crush them.

10. Gloom - Gloom has the ability to create a cloud of darkness around him, obscuring his enemies' vision.

11. Grub - Grub has a bloated, distended belly that allows him to store large amounts of food and water.

12. Blight - Blight has a poisonous touch, causing his enemies to become sick and weak.

13. Scuttle - Scuttle has long, spindly legs that allow him to move quickly and silently.

14. Fang - Fang has long, sharp teeth that he uses to tear apart his prey.

15. Nub - Nub has small, vestigial wings that allow him to glide short distances.

The mutants are fiercely protective of their settlement and will attack anyone who intrudes on their territory. The adventurers will have to navigate through the settlement, avoid traps, and defeat the mutants if they hope to continue on their journey. The sounds of snarling, growling, and slurping add to the eerie and unsettling atmosphere of the encounter.