Page 74 of Tomb of Annihilation offers a small side-quest to raid a Pterafolk nest for Nanny Pu'pu. I created the following short dungeon to flesh out that quest. It was a challenging dungeon for four to five characters of 2nd to 3rd level. I included more pterafolk the first time I ran this - 4 in the shrine, 6 + 2 elders + 1 leader in the common area against 4 PCs at 4th level which pretty much ended with a TPK, so I reduced the number of pterafolk in this write-up. I also explicitly call out that the pterafolk wish to capture some prisoners alive in case you need to further dial back the carnage.
"Oh... you seek knowledge! Nanny Pu'pu knows many things. But knowledge has a price. There's ALWAYS a price!" The old woman's cackle sent the flying monkeys scattering.
She wheezed for a moment and regained her breath, "You want to know about the DEATH CURSE! Yes, the little monkeys have told Nanny Pu’pu about the dead things in the forest. Nanny Pu’pu does not cause it. Nanny Pu’pu can return life to the dead but only when the price is paid."
"Nanny Pu’pu knows the answer to your questions. But she will answer no questions unless you bring Nanny Pu’pu a gift. Yes. Bring her a gift and pay the price."
"Hidden in the rocks on the south side of this tepui is a nest of pterafolk, wretched things that eat Nanny Pu'pu's little monkeys. Bring to Nanny Pu’pu one of their wretched eggs, or better one of their wriggling young, and Nanny Pu’pu will answer your questions. The price must be paid. Yes."
The city of M'Bala is located on top of a type of large granite monolith called a tepui. The tepui rises a thousand feet above the surrounding jungle-clad hills.
The flock of Pterafolk that Nanny Pu'pu detests make their home in a cave 30 feet below the southern lip of the plateau. Nanny Pu'pu finds them annoying because they catch and eat her flying monkeys.
The entrance into their cave can be reached by climbing down the cliff face. Climbing down is automatic but anyone who fails a DC 10 Strength (Athletics) check takes 1d6 bludgeoning damage while doing so.
Characters who carefully scout the area overlooking the cliff face and succeed on a DC 13 Wisdom (Perception) check will locate a fissure in the rocks 70 feet back from the cliff. This narrow fissure is wide enough for a Small creature, or for a Medium creature who's wearing nothing heavier than light armor, to squeeze through. After worming down 30 feet, it connects to the fissure in Area 4. No climbing check is necessary.
The pterafolk post no watch. They believe that the inaccessibility of the entrance is sufficient to deter intrusion.
The caves are unlit. Pterafolk seem to lack fire so they do not illuminate their caves with torches or campfires. Since pterafolk cannot see in the dark they simply move through their darkened lair blind, feeling their way around with their hands like animals in any burrow, . Characters with darkvision may fight in the complete darkness while pterafolk suffer Disadvantage on all attack rolls, saving throws, and skill checks. Indeed, characters with darkvision, operating in the complete darkness of the cave and with sufficient Dexterity (Stealth) skill checks, might infiltrate the lair and move about unnoticed by the pterafolk around them.
Characters who bring illumination such as torches or lanterns or light spells will eliminate Disadvantage for both sides but will also eliminate any chance for stealth or a surprise attack.
Pterafolk enter and exit the lair via this ledge overlooking the sheer face of Mbala. the entrance is located 75 feet below the lip of the flat top of Mbala. The entrance is covered in white lumpy excrement that trails down the face. Much of the excrement contains the partially digested remains, fur, and bones of animals, batiri, and people. There are two pterafolk utilizing the ledge. The passage in the rear climbs a steep ten foot tall ledge leading to Area 2. There is no line of sight between Area 1 and Area 2 and the howling winds outside the area mask most loud sounds such as that of a battle.
At the conclusion of any battle, one of the pterafolk from Area 2 will shout an inquiry in the Common tongue asking what all the noise was about. They are busy eating and will accept any reasonable response. An inadequate answer will alert the pterafolk in Area 2 that something is afoot. One will rush to Area 5 to warn the others.
Ten minutes after the player characters enter Area 1, one of the pterafolk from Area 2 will enter the area to utilize the ledge.
The pterafolk worship a dark god (in Faerun they worship Shekinester, goddess of spirit nagas, but the precise identity of the deity is not important). A totem to their dark god stands erect in the center of the room surrounded by small offerings. Any pterafolk standing within five feet of the totem gains advantage on attack rolls, saving throws, and skill checks. Any non-pterafolk standing within five feet of the totem gains disadvantage on attack rolls, saving throws, and skill checks.
There are currently three pterafolk (two if one left to investigate Area 1 or if one went to Area 5 to warn the others) eating a ritual meal of raw meat. At the first sign of intruders, if it hasn't already done so one will immediately disengage and flee towards Area 5 to warn the others.
Pterafolk store their meat in this dark cool chamber. It is filled with the half-eaten bodies of dead animals, batiri, and two human explorers.
Treasure: Among the human bodies is a backpack that contains 6 gp in a pouch, a journal*, a silvered dagger, and a potion of greater healing.
* The journal allows the DM to provide any additional exposition they wish regarding the quest for the Soulmonger, the state of Camp Vengeance, or any hooks that might lead characters to places such as Orolunga or the Heart of Ubtao.
This fissure is twenty feet wide and leads all the way to the top of Mbala, allowing sunlight and rain to filter down through the cracks. Medium sized creatures can squeeze through the crack at the top and climb down 75 feet. Crossing the fissure by clinging to the walls and climbing around requires a successful DC 10 Strength (Athletics) check. A failure results in the character taking 1d6 bludgeoning damage as they fall 10 feet and hit their head before they catch themselves.
Anyone with a Strength of 10 or better and a ten foot running start can leap the ten foot gap to the north passage, anyone with a Strength of 15 or better and a ten foot running start can leap the fifteen foot gap to the south passage. No skill check is required.
5. Common Area
This large chamber is where the pterafolk sleep and breed. The ceiling is 40 feet tall. The passage from the south descends 30 feet like a ramp and opens onto the floor of the chamber. The passage on the east wall opens onto a stone platform 30 feet above the floor of the chamber. A 10 foot tall barrier juts from the west wall towards the northern end of the chamber. The floor is littered with debris, twigs, sticks, branches, and other detritus used to make the pterafolk nests.
There are nests for up to twenty pterafolk but at any given time one can expect to encounter four pterafolk, two elder pterafolk (13 hp), and one leader pterafolk (40 hp). If a group of intruders were to enter from the south passage, the pterafolk will split into two equal groups. Half will advance on the intruders to keep them in the south passage. The other half will fly to the east passage and looping around via Area 4 to trap the intruders.
The pterafolk will attempt to capture any intruders alive if they can for interrogation and possible consumption.
This chamber is a communal hatchery where all the pterafolk eggs are stored. There are a handful of batiri and grung as well as few native Chultan human children held captive here. They were captured from the jungle and carried here. They were meant to be served as a first meal to the newly emerged hathlings.
Treasure: A handful of precious gems are encrusted in the wall. These precious gems may be pried loose and removed. Each gem is worth 100 gp. Both the gems and the prisoners are suitable for use in Nanny Pu'pu's Ritual of Stolen Life. The exact number of gems and prisoners is up to the DM and should be used to tempt players into considering performing the necromantic ritual.