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The Handy Haversack

Level 8: Slitherswamp

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Slitherswamp is designed for four 10th-level characters, and characters who defeat the monsters on this level should gain enough XP to reach halfway to 11th level. This level consists of muck-filled caverns and decaying temples dedicated to evil deities of the yuan-ti. The serpent folk lived here until they were defeated by nagas known as the Ssethian Scourges. Afterward, Halaster replaced the yuan-ti with a bullywug tribe governed by a cruel death slaad overlord.

What Dwells Here?

Adventurers might find themselves caught up in the war of Slitherswamp by encountering the thralls of the Ssethian Scourges, the Blacktongue bullywug tribe, the meddling ghost of a yuan-ti priest (see area area 9), or watchful agents of the Dweomercore mages of level 9.

The Ssethian Scourges

The Ssethian Scourges were three spirit nagas that fought the yuan-ti of the Slitherswamp, eventually claiming victory. Only two spirit nagas remain, Excrutha and Serakath, along with their thralls and the remnants of the third spirit naga, Hexacali, who was destroyed and transformed into a bone naga by the yuan-ti.

The spirit nagas maintain a stable of thralls and use a rod of rulership to insure their obedience. Every day at dawn, the nagas gather their thralls in area area 15a and target them again with the recharged rod, and each naga has the special ability to increase the duration of the charm effect to 12 hours. Humanoid thralls that resist the rod’s magic often choose to maintain the appearance of being charmed for the sake of their own survival, because the nagas kill or chain up those they can’t magically enslave.

Shortly after the Ssethian Scourges defeated their yuan-ti foes, a tribe of bullywugs led by a death slaad appeared in the Slitherswamp. Frustrated by this new obstacle to their dominance of the level, the nagas now seek allies to slay the bullywugs and their leader. The nagas know the locations of all the magic gates on this level, as well as how to activate them. They share that information with creatures that willingly serve them.

The Blacktongues

A year ago, Halaster used his magic to transport the Blacktongue tribe of bullywugs, along with its small army of giant frogs and giant toads, from a remote marshland to this level of Undermountain. He seeded them into those parts of Slitherswamp once controlled by the yuan-ti. The bullywugs were quick to capture and domesticate four carrion crawlers and a hydra.

Halaster also summoned a death slaad named Kuketh to Slitherswamp. The Mad Mage keeps the slaad’s control gem in his sanctuary on level 9 and forces Kuketh to serve as the bullywugs' king. The Blacktongues live in fear of their new king, whom they call Yurk Y’blorkflug (“lord of fetid obliteration” in their language). The slaad hates being under Halaster’s control and takes out its frustration on its subjects.

Carrion Crawler Mucus

Blacktongue bullywugs coat their weapons with carrion crawler mucus. A creature hit by a bullywug’s Spear attack must succeed on a DC 13 Constitution saving throw or be poisoned for 1 minute. A creature poisoned in this way is also paralyzed. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Karstis of Dweomercore

The mages of Dweomercore (level 9) have sent one of their own, a human named Karstis, to monitor this level. He hides in area areas 7 and area 8 with his minions. Karstis is an ally of those looking to thin out any of the factions in Slitherswamp, but a foe to anyone who tries to gain access to Dweomercore.

Exploring This Level

All location descriptions for this level are keyed to map 8. Many tunnels and caves of Slitherswamp are partially flooded with water, ranging from a few inches to several feet in depth, over a layer of thick mud. Areas marked as swamp on the map are difficult terrain for any creature that lacks a swimming speed.

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(Player Version)

This entire level is wet and humid. Ordinary frogs, toads, and insects thrive here.

1. Precipice

The sloping tunnel from level 7 ends 20 feet above the marshy ground of area 2.

Humidity. The walls and floor of the tunnel drip with moisture from the humidity, and buzzing insects are everywhere.

Rope Ladder. The crumbling remains of a ramp lie below the precipice. A slimy rope ladder has been anchored with spikes to its western edge.

The rope ladder has been smeared with carrion crawler mucus. Any creature climbing down the ladder must succeed on a DC 13 Constitution saving throw or be poisoned for 1 minute. A creature poisoned in this way is also paralyzed and falls from the rope ladder into the muck of area 2 below, taking 3 (1d6) bludgeoning damage. The creature can repeat the saving throw at the end of each of its turns, ending the mucus’s effect on itself on a success.

2. Bullywug Sentries

Ceiling. This swampy cavern has an uneven 30-foot-high ceiling.

Fireflies. Harmless fireflies flit over strange fungal plants that sprout from the swamp, filling the cavern with eerie dim light.

Bullywugs. Three Bullywug use their Swamp Camouflage feature to hide in the swampy tunnel leading to area area 19.

The bullywugs watch the tunnel that leads to level 7. When they spot the characters, three of them try to sneak away to area areas 19a and area 20, to warn the rest of the tribe. The others wait to see where the intruders go.

3. Arch Gate to Level 6

A three-forked passageway rises out of the swamp. The center passage has an arch embedded in its back wall. This arch is one of Halaster’s magic gates (see “area Gates"). The space inside it bears a bas-relief of a female dwarf standing with her eyes closed. A keyhole is carved into the head of a stone hammer she clutches to her chest. The rules of this gate are as follows:

  • If the stone key from area area 14a on level 2 is inserted into the keyhole, the bas-relief and the key vanish as the gate opens for 1 minute. When the gate closes, the bas-relief reappears, and the key is ejected from its keyhole.
  • A character can open the gate without the stone key by using an action to pick the lock, requiring a successful DC 20 Dexterity check using thieves' tools. If the check fails, the dwarf’s eyes open and emit light. Each creature within 10 feet of the arch must make a DC 16 Dexterity saving throw, taking 22 (4d10) radiant damage on a failed save, or half as much damage on a successful one.
  • Characters must be 9th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 34b on level 6, in the closest unoccupied space next to the identical gate located there.

4. Dangerous Shrubbery

A 20-foot-high dry ledge (area 4a) overlooks a 30-foot-high cavern filled with vegetation and ankle-deep mud (area 4b). This area’s features are as follows:

Vegetation. Luminescent, fern-like plants sprouting from the mud fill this area with dim light.

Severed Limb. Part of the ledge wall is stained with blood. Directly below the stain, a severed leg wearing a sturdy boot sticks up out of the mud.

4a. Final Rest of Thubid Duskaxe

This 20-foot-high ledge can be climbed with a successful DC 15 Strength (Athletics) check. Atop the ledge, above the bloodstain but not visible from the tunnel floor, the body of a duergar sprawls near a campsite. The corpse is that of Thubid Duskaxe, a duergar adventurer on a rescue mission. He lost a leg when he fought the shambling mounds and subsequently bled to death.

Treasure

The corpse wears a leather satchel that contains 224 gp, an ornate stone carving of an owl (50 gp), and a journal written in Dwarvish. The journal contains a map showing areas 1 through 6, as well as notes of “frog people to the northeast” and “serpents with foul magic to the southeast.” The journal describes Thubid’s plan to find allies to help him rescue his cousin, Agorra, who was “bewitched by the serpents.”

4b. Shambling Mounds

Any character who succeeds on a DC 12 Wisdom (Perception) check is not surprised when three Shambling Mound attack. The shambling mounds chase creatures through the mud but ignore creatures atop the ledge.

5. Dry Cave

This dry, 20-foot-high cavern stands empty and serves as a good place to rest on this level.

6. Reflections

This swampy cavern has a 50-foot-high ceiling of jagged rock. Rising from the mire is an island of dry rock, upon which are the following features:

Ruins and Statue. Amid the ruins of a dome built of black stone is a statue of a snake with closed eyes swallowing its own tail.

Apparition. The ghostly image of an adventurer moves through the area, looking lost.

The ghostly image of a male human warrior in plate armor wanders around the statue as though searching for something he has lost. The image cannot be harmed and does not acknowledge the characters. If a character dies on this level, the image changes to appear as that character, even if the character is later raised from the dead. A dispel magic spell that targets the image causes it to disappear for 1 hour.

A successful DC 15 Intelligence (Religion) check suggests that the statue is a representation of Dendar the Night Serpent, the yuan-ti god of nightmares. Any character who touches the statue is cursed. Until the curse is ended with a remove curse spell or similar magic, the character is beset by nightmares and gains no benefit from a long rest.

7. Warded Cavern

A glyph of warding spell has been cast on the floor at the center of the 10-foot-high cavern. The glyph triggers a cloudkill spell (save DC 15) when any creature other than Karstis passes the midpoint of the cavern. The spell’s cloud lasts for 10 minutes.

8. Dweomercore Hideout

These caves are used by the mages of Dweomercore (level 9) to keep an eye on their neighbors. The caves' inhabitants include a mage named Karstis.

If death or capture seems likely, Karstis grabs his spellbook in area 8b and flees to level 9 after instructing his bodyguards to cover his escape. Thereafter, Karstis can be encountered in area 8c on level 9.

8a. Guards

Golem. A flesh golem stands watch in the middle of this 10-foot-high cave, facing the entrance.

Wights. Two Wight are on guard at the south end of the cave (outside area 8b).

Crates. Three open crates are stored in the westernmost alcove. They contain sheets of parchment, small jars of ink, quills, 10 days of edible rations, and five 2-gallon casks of clean water.

If the glyph in area area 7 triggers, the flesh golem and the wights can’t be surprised. The golem was crafted by Wormriddle the night hag (see area level 9). If the golem goes berserk, neither Karstis nor any of his other servants can regain control of it.

8b. Karstis’s Cave

Karstis (LE male Mulhorandi human mage) lurks here with four Minotaur Skeleton. The 10-foot-high cave is lit by a hooded lantern that rests on a portable writing desk covered in quills, ink jars, and books. A folding cot rests near the back wall.

Treasure

Amid the clutter on the desk, characters can find Karstis’s spellbook. The book is bound in human flesh and contains all the spells Karstis has prepared, plus animate dead and glyph of warding.

9. Temple of the Great Snake

This 30-foot-high cavern is dominated by a ruin that contains the following:

Carvings. The interior walls are covered in carvings of snakes, fanged maws, and open ophidian eyes.

Black Statue. The northwest section of the temple contains a black stone statue of a masked, hooded male humanoid dressed in leather armor and clutching a dripping dagger in each hand. Harmless centipedes crawl all over the statue.

Green Statue. The middle chamber contains a statue carved of green stone, depicting a 15-foot-tall winged snake with its fangs bared. Harmless snakes slither around the statue’s base.

Ghost. Wandering through the ruin is a spectral woman wearing a soiled black gown and a featureless white mask (actually the ghost of a slain yuan-ti priest).

A yuan-ti pureblood priest named Yoastal was slain by the Ssethian Scourges and remains bound to the temple. Because she cannot leave, she tries to trick others into completing her unfinished business, knowing that she cannot rest until the Ssethian Scourges are dead.

Yoastal can be both friend and foe to an adventuring party. The ghost claims to have once been a cleric of Mask, cursed to remain in Slitherswamp until the nagas are destroyed. She provides characters with the layout of the level in exchange for promises to free her. But her information is always slanted toward leading the characters into situations that might further escalate the war between the Ssethian Scourges and the Blacktongues.

If Yoastal is destroyed while any of the nagas live, she re-forms in this ruined building in 1d4 days.

Black Statue

Water trickling down from the ceiling falls onto this statue and drips off its daggers like poison. A character who succeeds on a DC 15 Intelligence (Religion) check recognizes the statue as a representation of the yuan-ti god Sseth.

A character who searches through the mud around the statue and succeeds on a DC 15 Wisdom (Perception}) check discovers a rotting sack and also digs up a hostile {@creature swarm of insects (centipedes).

Treasure

The sack contains 550 gp.

Green Statue

A character who succeeds on a DC 15 Intelligence (Religion) check recognizes this statue as another representation of Sseth.

10. Rainfall Caverns

Water pours from the ceiling of these 20-foot-high caves like a heavy rain. Consequently, creatures in this area have disadvantage on Wisdom (Perception) checks that rely on sight or sound.

10a. Venom Pool

This cavern is flooded to a depth of 4 feet. The water glows green around an emerald that lies on the floor in the middle of the cavern. This gemstone has been blessed by Sseth, such that it turns the water around it to poison. Any creature that starts its turn in the water must make a DC 12 Constitution saving throw, taking 11 (2d10) poison damage on a failed save, or half as much damage on a successful one. Water that leaves the cavern is no longer poisonous, and the water in the cavern ceases to be poisonous once the emerald is removed from it.

Treasure

The flawed emerald loses its magic if taken from the area and is worth 250 gp.

10b. Hissing Stone

In the middle of this cavern, a large stone rises above the 3-foot-deep water and magically emits a soft hissing sound. The natural pattern of the stone vaguely resembles a swarm of snakes.

A character who touches the stone hears a sibilant whisper asking that individual to ask a question aloud. If the character does so, the voice answers as if the character had cast the augury spell. Once the stone is used in this way, it cannot be used again until the next dawn.

11. Watch Post

This area is guarded by thralls of the Ssethian Scourges against possible attack from the Blacktongues.

11a. Flooded Cave

This 20-foot-high cavern is flooded with muddy water to a depth of 3 feet. The drow in area 11b attack intruders they spot moving through this cave.

11b. Watchers in the Dark

Dry land rises gently out of the water to create a broad ledge dotted with 4-foot-high piles of loose rocks. Two Drow Elite Warrior, a female named Dirzanna Freth and a male named Arachnafein Zaphrorzza, hide behind the rocks. These drow are under the effect of the spirit nagas' rod of rulership and move to the swamp’s edge to attack intruders detected in area 11a. If enemies close to melee range, the drow switch to melee weapons.

If one drow elite warrior falls in battle, the other tries to flee to area 13 and alert the creatures there. The drow have orders from the spirit nagas to capture intruders if possible, meaning that any character reduced to 0 hit points by a drow’s melee weapon attack is knocked unconscious. Characters captured by the drow are brought before the nagas in area area 15.

If and when the charmed condition on them ends, Dirzanna and Arachnafein make their way to House Freth’s base on level 12.

12. Fishery

This small cave has a 10-foot-high ceiling and contains a 20-foot-deep pool with a crevasse at the bottom, through which cold water bubbles up from a natural spring. The thralls of the Ssethian Scourges use the sightless cave fish that swim here as a source of food.

13. Detention Cave

A male drow elite warrior named Xirk Dezpeti’il is chained to one of three sets of manacles that hang from the west wall. The nagas use the manacles to bind creatures that resist the magic of their rod of rulership.

A sometime adventurer and unrepentant ne’er-do-well who pledges alliance to no one, Xirk is willing to trade information about the surrounding caves or the thralls' routine in exchange for freedom to return to the Underdark. If he is freed, he avoids combat and is not above stealing from his benefactors.

14. Fungal Farm

Two tunnels lead into this damp, 10-foot-high cavern, which contains the following features:

Spores. A perpetual haze of spores fills the air, making the area lightly obscured.

Fungi. Small fungi are planted in neat rows and are used as a fast-growing food crop. A pile of gardening tools lies by the west tunnel entrance.

15. Lair of the Spirit Nagas

All the caves of area 15 are either dry or have their floors covered with 1 foot of muddy water.

An alarm raised in any of these areas attracts all nearby creatures: the spirit nagas in area area 15c, as well as their thralls in area areas 11b, area 15c, and area 15f. The spirit nagas and their thralls avoid killing humanoid intruders if they can. Prisoners who can’t be enslaved are thrown into the arena (area 15a) without their weapons and forced to fight to the death against the nagas' thralls.

15a. Arena

The Ssethian Scourges sometimes have their thralls fight captives for their amusement. This 40-foot-high cave has the following features:

Ledge. A slope of dry land rises from a few inches above the water to a 20-foot-high ledge at area 15b.

Weapons. Shattered and abandoned weapons lie in the wet muck. (Characters forced to fight here can easily recover serviceable melee weapons from the muck and detritus.)

15b. Naga Thrones

The north side of the ledge drops away 20 feet to the arena floor (area 15a). Two flat stones command a view of the arena and are used as thrones by the nagas.

15c. Steamy Den

This cramped, steam-filled cave contains the following:

Duergar Thrall. Agorra Duskaxe, a female duergar, stands guard just inside the entrance.

Steamer. Water dripping from a crack in the ceiling falls into a cylindrical metal contraption at the center of the cave, and steam billows out of it.

Nagas. Unless they have been drawn elsewhere, two Spirit Naga named Excrutha and Serakath lounge on the floor near the back of the cave (see “area The Ssethian Scourges").

Chest. A wooden chest stands against the east wall.

The nagas don’t fear death, but they do fear the loss or theft of their rod of rulership and will do everything they can to safeguard it. A battle here attracts the thralls from area areas 11b and area 15f, assuming they’re still around.

While Agorra is under the effect of the rod of rulership, she believes the nagas to be her allies and defends them to the death. She carries the key to the manacles in area area 13.

The steamer consists of two iron chambers stacked on top of each other. Magical fire burns in the bottom chamber, heating water that pours into the top chamber through the crack in the ceiling. Small holes in the sides of the top chamber allow steam to vent into the cave, keeping it warm and moist.

Treasure

One spirit naga has a rod of rulership coiled in its tail at all times. The rod’s magic has been spent for the day and can’t be called upon again until the next dawn.

The chest is unlocked and contains 500 pp, 330 gp, a silver necklace in the form of entwined serpents (250 gp), and a spell scroll of modify memory.

15d. Unused Laboratory

A wooden table covered with alchemist’s supplies stands against the north wall of this damp, 10-foot-high cave.

15e. Spring

A steady stream of water pours out from a crack in the wall of this alcove. The water fills up a natural stone basin, which in turn overflows onto the muddy ground. This spring provides clean water.

15f. Troll Guard Post

Two Troll charmed by the nagas' rod of rulership are crammed in this alcove until they are drawn elsewhere.

16. Lair of the Bone Naga

Bones. This 30-foot-high cave appears empty except for the bones of numerous creatures (humanoids and yuan-ti) visible beneath the water.

Hexacali. Lurking amid the bones is a Bone Naga (Spirit) (formerly a spirit naga named Hexacali).

The bone naga tries to slay any living creature that enters its domain. Creatures moving through this area must succeed on a DC 15 Wisdom (Perception) check or be surprised when the bone naga attacks.

17. Battlefield Cavern

This 30-foot-high cavern was the main front of the battle between the yuan-ti and the nagas.

17a. Bones in the Mud

The water here is 2 feet deep, and the cavern floor beneath it is littered with yuan-ti bones.

17b. Death of a Naga

The phantasmal scene of a spirit naga battling four yuan-ti purebloods plays out for characters who set foot on this island. As characters view the scene, they find themselves literally being drawn into it.

Each character drawn into the scene temporarily becomes one of the yuan-ti fighting the wounded Hexacali. The character gains the statistics of a yuan-ti pureblood with 2d20 hit points remaining.

Hexacali, a spirit naga with 35 hit points, is trapped on the island and fights yuan-ti characters to the death. Yuan-ti characters who drop to 0 hit points during this fight immediately come to their senses and take 22 (4d10) psychic damage from the shock of their illusory demise. Unlike any damage sustained in the battle, this psychic damage is real. A character free of the vision can free another character from it by using an action to shake or slap them.

If the characters defeat Hexacali, their last collective memory is of pinning the naga down to be slain and raised as a bone naga. The vision then ends for all characters and can’t take hold of them again.

17c. Mirror Gate to Level 10

A wedge of dry land rises from the water to become the floor of a 15-foot-high cave with a mirror mounted to its eastern wall.

The mirror is framed by an assemblage of hundreds of tiny interlocking stone gears. This mirror reflects normally and is one of Halaster’s gates (see “area Gates"). Its frame is composed of an assemblage of hundreds of tiny, interlocking stone gears. This gate’s rules are as follows:

  • Any creature that inspects the frame and succeeds on a DC 15 Wisdom (Perception) check sees that one of the gears has popped out slightly. If it is pressed, the gear locks in place, causing all the gears to turn and the gate to open for 1 minute. When the gate closes, a different random gear pops out slightly, causing all the gears to lock again.
  • Characters must be 11th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 25b on level 10, in the closest unoccupied space next to the identical gate located there.

18. Serpent Gate

These 10-foot-high side caverns feature a standing gate that grants access to level 11. Strikingly beautiful carvings of serpents decorate the walls of these caverns.

18a. Trapped Approach

An old yuan-ti trap meant to prevent approach to the gate still functions in this area. A pressure plate under the water and mud extends the full width of the cavern entrance. A character searching the cavern for traps who succeeds on a DC 20 Wisdom (Perception) check spots the pressure plate. The trap triggers whenever a weight of 50 pounds or more is placed on the pressure plate. Darts fire from holes in the walls against the creature that triggered the trap, making a ranged weapon attack (+7 to hit) that deals 10 (4d4) piercing damage. The trap resets each round.

A search of the walls and a successful DC 20 Wisdom (Perception) check is sufficient to spot small holes in the serpent carvings. The characters can spend 1 minute to plug the holes, which prevents the trap from attacking. The pressure plate can be disabled with a successful DC 15 Dexterity check using thieves' tools.

18b. Standing Gate to Level 11

Two pillars with giant stone snakes wrapped around them rise from the muck. Chiseled into the lintel stone across the top are the words “DON THE CRYSTAL CROWN” in Dwarvish. This gate’s rules are as follows:

  • The gate opens for 1 minute if a creature wears King Melair’s crystal crown (see area level 6, area 11d) while standing within 5 feet of it.
  • Characters must be 11th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 11a on level 11, in the closest unoccupied space next to the identical gate located there.

19. Yuan-ti Temple

The roof of this cavern soars to a height of 80 feet, and the muddy water throughout is 2 feet deep. Dominating the cavern is a ruined yuan-ti temple filled with statues depicting the same winged serpent with its fanged mouth open. A character who succeeds on a DC 15 Intelligence (Religion) check recognizes the statues as depictions of Sseth, a yuan-ti deity. Flickering torches on the sides of the temple illuminate the structure.

19a. Amphibious Guards

Eight Bullywug and three Giant Frog stand guard in the water outside the temple. The bullywugs try to paralyze intruders using their spears, the tips of which are coated with carrion crawler mucus. Characters paralyzed by the bullywugs' spears or swallowed by the giant frogs are brought to area area 19d and held there until Kuketh can be summoned from area area 20 to devour them.

19b. Narthex

A 10-foot-tall statue of a winged serpent stands at the entrance of the temple between two submerged stone ramps. The ramps are slippery and rise to meet the floor of a 20-foot-high antechamber, the floor of which is submerged under 1 foot of murky water.

Decorative columns carved to look like intertwined snakes line the chamber’s walls.

19c. Nave

Water. Murky water covers the floor to a depth of 1 foot.

Ceiling Fresco. This chamber has a vaulted ceiling 30 feet high. A fresco on the ceiling has mostly crumbled away, but the portions that remain suggest serpentine images that were probably quite fearsome.

Statues. Four statues of winged serpents stand to the north, two in the water and two above the waterline. (Torbit, a bullywug assassin, hides behind the partially submerged statue in the northwest corner.)

Platform. Between the two middle statues, a mostly submerged ramp rises to the top of a dry platform, at the back of which is a closed door that opens into area 19d.

Torbit might have become king of the Blacktongues if not for his devotion to Kuketh. He jealously protects the temple that is his master’s seat of power, killing any who enter without permission. Torbit is an assassin, with these changes:

  • Torbit is chaotic evil.
  • He has these racial traits: He can breathe air and water. He speaks Bullywug, and can speak with frogs and toads. He has a walking speed of 20 feet and a swimming speed of 40 feet. His long jump is up to 20 feet and his high jump is up to 10 feet, with or without a running start. He has advantage on Dexterity (Stealth) checks made to hide in swampy terrain.
  • In addition to his weapons, Torbit carries one piece of a shattered jade staff (see “Treasure” below).
Treasure

The foot-long piece of jade that Torbit carries was found in the muck. He doesn’t realize that it’s a fragment of a jade staff crafted by ancient yuan-ti that was discarded in Undermountain by Halaster years before. See area area 39b on level 6 for more information on this yuan-ti device and how it can be reassembled. By itself, the jade fragment is worth 100 gp.

19d. Apse

This 30-foot-high chapel has the following features:

Mud-Caked Statue. Dried mud has been heaped onto a large, winged snake statue to the north, giving it a vaguely frog-like appearance. Poor-quality carved offerings and worthless stones are piled before the statue.

Altar. A stone altar in the center of the room bears carvings of serpents.

Any character who inspects the altar and succeeds on a DC 15 Wisdom (Perception) check notices that one of the altar’s carvings has a button carved to look like a serpent’s eye. If this button is pressed, a secret compartment on the north side of the altar opens. Inside this compartment is a slender red taper (see “Treasure” below). Kuketh and the bullywugs are unaware of the altar’s hidden compartment and the treasure within.

Treasure

The red taper is a candle of invocation dedicated to Sseth, the neutral evil yuan-ti god. If the candle is removed from the altar by a creature that is not a yuan-ti, green mist billows up through cracks in the floor and coalesces into two Yuan-ti Abomination. These temple guardians attack any creature that is not a yuan-ti. When reduced to 0 hit points, they revert to clouds of green mist and disappear without a trace.

If the yuan-ti abominations are not killed, they rid the temple of enemies and turn it into their lair.

20. Blacktongue Isle

Deep Water. The ground falls away at all entrances to this 30-foot-high cavern, whose water is 30 feet deep.

Island Village. A dozen crude shacks sit atop a muddy, horseshoe-shaped island. Twenty-five Bullywug and six Giant Frog slip in and out of the shacks.

Bonfire. A bonfire burns at the northern tip of the island, giving off pungent smoke. (The bullywugs keep it burning with a mixture of dried offal and fungus.)

The shacks are made from rocks mortared with mud. The bullywugs found here are busy raising young, mending nets, cooking, or working on other domestic necessities. They and the giant frogs are quick to respond to calls for aid from area area 19.

Harmless cave fish swim in the deep water around the island. The pool at the island’s center is closed off by a submerged net that prevents fish from finding their way inside. The Blacktongues keep their unborn eggs in this pool, hidden among submerged stands of thick-fronded fungus.

21. Lord of Fetid Obliteration

Unless he has been summoned to area area 19, the unhappy king of the Blacktongues is here.

21a. Hydra Den

This cave has a 20-foot-high ceiling and is filled with water to a depth of 30 feet. Lurking in the muddy water at the bottom of the cave is a trained hydra. The hydra refrains from announcing its presence or attacking until such time as Kuketh orders it to rise and kill something.

21b. Kuketh’s Lair

Ledge. A dry ledge 5 feet above the water line is strewn with bones, some with flesh still attached.

Kuketh’s Bed. The eastern end of the ledge contains a pile of moldering hay and the rotting body of a giant toad. Unless it has been drawn elsewhere, Kuketh the death slaad lounges on the hay in bullywug form.

When not bossing around its subjects, Kuketh quietly ruminates on its troubles. The slaad communicates with strangers using telepathy and is willing to negotiate with characters who claim to be enemies of the Ssethian Scourges. A mercurial creature, Kuketh doesn’t honor agreements for very long. Its only consistent desire is to escape from Undermountain and return to the Outer Plane of Limbo.

21c. Secret Vault

This cave is hidden behind a secret door.

Treasure

The vault holds treasure collected by the bullywugs, including 56 pp, 2,417 gp, 540 sp, a platinum holy symbol of Sseth (a flying snake with bared fangs) worth 150 gp, and a headband of intellect.

22. Stables

The Blacktongue bullywugs raise “livestock” in this 20-foot-high, torch-lit cavern. If the bullywug handlers here are attacked, they release their carrion crawlers and shout for aid from area areas 19 and area 23.

22a. Giant Frogs

Six giant frog hop through shallow water in this cavern, croaking loudly while four Bullywug dump food (mostly vermin) into a trough along the northwest wall.

22b. Carrion Crawlers

This raised dry area contains the following:

Wooden Pen. A pen made of wooden slats confines four Carrion Crawler to the northeast. Three carrion crawler eggs are inside the pen.

Tools. Several buckets and long-handled tools for wrangling the carrion crawlers stand near the gate to the pen.

The bullywugs raise carrion crawlers for their poisonous mucus, but they also feed carrion crawler eggs to the hydra in area area 21a. The carrion crawlers are not treated well. If released, they are as likely to attack the bullywugs as they are the characters.

Wood scraps gathered from throughout the level have been used to fence off this dry area from floor to ceiling. The gaps between the slats are just wide enough for a melee weapon or a carrion crawler’s tentacle attack. A simple loop of rope keeps the gate closed.

23. Bullywug Camp

Muck. This 20-foot-high cave is filled with muck to a depth of 1 foot.

Bullywug Shacks. Two hovels made of stones and mud are lit by tall torches. Four Bullywug are mending tools near the shacks while two Giant Toad look on.

24. Kelp Farm

Five Bullywug work kelp beds in the 6-foot-deep water of this 30-foot-high cave, while a giant toad swims nearby. The kelp is a staple of the bullywugs' diet and glows with a faint green light. The light fades 10 minutes after the plant is harvested.

If they are threatened, the bullywugs order the giant toad to attack and call for help from area areas 2 and 23.

Aftermath

If the characters help Kuketh destroy or reclaim its control gem, the death slaad abandons the bullywugs. If Torbit is alive, he becomes the ruler of the Blacktongue tribe after Kuketh departs or is killed. It’s only a matter of time, however, before the Ssethian Scourges seize him, make him one of their thralls, and take control of the bullywug tribe. If all the Blacktongue bullywugs are defeated, the temple becomes a safe place for the characters to rest (assuming the yuan-ti abominations in area area 19d haven’t taken over the place).

Killing the Ssethian Scourges frees Yoastal from her curse and allows the Blacktongues to overrun the nagas' caves. Karstis and the mages of Dweomercore might be there already, though, wanting to hold those caverns. Such gains are short-lived, because the spirit nagas' Rejuvenation trait ensures their return in 1d6 days.