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Aboleth

• Size: Large
• Type: Aberration
• Alignment: Lawful Evil
• AC: 17
• Initiative: +7 (17)
• HP: 150(20d10+40)
• Speed: 10 ft, Swim 40 ft .

ATTR	VAL	MOD	SAVE
STR	21	+5	+5
Dex	9	-1	+3
Con	15	+2	+6
INT	18	+4	+8
Wis	15	+2	+6
CHA	18	+4	+4

• Skills: History +12 , Perception +10
• Senses: Darkvision 120 ft.; Passive Perception 20
• Languages: Deep Speech; telepathy 120 ft.
• CR: 10 (XP 5,900, or 7,200 in lair; PB+4 )

Traits

Amphibious. The aboleth can breathe air and water.

Eldritch Restoration. If destroyed, the aboleth gains a new body in 5d10 days, reviving with all its Hit Points in the Far Realm or another location chosen by the GM.

Legendary Resistance (3/Day, or 4/Day in Lair). If the aboleth fails a saving throw, it can choose to succeed instead.

Mucus Cloud. While underwater, the aboleth is surrounded by mucus. Constitution Saving Throw: DC 14, each creature in a 5 -foot Emanation originating from the aboleth at the end of the aboleth's turn. Failure: The target is cursed. Until the curse ends, the target's skin becomes slimy, the target can breathe air and water, and it can't regain Hit Points unless it is underwater.

While the cursed creature is outside a body of water, the creature takes 6 (1d12) Acid damage at the end of every 10 minutes unless moisture is applied to its skin before those minutes have passed.

Probing Telepathy. If a creature the aboleth can see communicates telepathically with the aboleth, the aboleth learns the creature's greatest desires.

Actions

Multiattack. The aboleth makes two Tentacle attacks and uses either Consume Memories or Dominate Mind if available.

Tentacle. Melee Attack Roll: +9 , reach 15 ft . Hit: 12 (2d6+5) Bludgeoning damage. If the target is a Large or smaller creature, it has the Grappled condition (escape DC 14) from one of four tentacles.

Consume Memories. Intelligence Saving Throw: DC 16, one creature within 30 feet that is Charmed or Grappled by the aboleth. Failure: 10 (3d6) Psychic damage.

Success: Half damage. Failure or Success: The aboleth gains the target's memories if the target is a Humanoid and is reduced to 0 Hit Points by this action.

Dominate Mind (2/Day). Wisdom Saving Throw: DC 16, one creature the aboleth can see within 30 feet. Failure: The target has the Charmed condition until the aboleth dies or is on a different plane of existence from the target. While Charmed, the target acts as an ally to the aboleth and is under its control while within 60 feet of it. In addition, the aboleth and the target can communicate telepathically with each other over any distance.

The target repeats the save whenever it takes damage as well as after every 24 hours it spends at least 1 mile away from the aboleth, ending the effect on itself on a success.

Legendary Actions

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature's turn, the aboleth can expend a use to take one of the following actions. The aboleth regains all expended uses at the start of each of its turns.

Lash. The aboleth makes one Tentacle attack. Psychic Drain. If the aboleth has at least one creature Charmed or Grappled, it uses Consume Memories and regains 5 (1d10) Hit Points.

Lore & Background

Aboleths are among the oldest and most alien creatures in existence, predating even the gods themselves. These ancient aberrations claim to remember the primordial times before mortals walked the earth, and their vast intellects harbor knowledge lost to history. They dwell in the deepest waters, building vast underwater cities where they rule over enslaved populations of various aquatic creatures and dominated surface dwellers.

An aboleth's body secretes a transformative mucus that gradually changes air-breathing creatures into water-dependent beings, ensuring a steady supply of servants. Their telepathic abilities allow them to probe minds, uncovering secrets and desires that they use to manipulate their victims.

These creatures view themselves as the rightful rulers of all existence, considering other beings as mere property to be owned and controlled. Their memories stretch back eons, making them repositories of ancient secrets, forgotten magic, and lost civilizations.

Combat Tactics

Aboleths are cunning combatants that prefer to avoid direct confrontation when possible. They typically begin encounters by using their Dominate Mind ability to turn enemies against each other, creating chaos and confusion. The aboleth focuses on isolating and controlling the most dangerous opponents first, particularly spellcasters and leaders.

When forced into melee combat, an aboleth uses its Multiattack to grapple multiple foes with its tentacles while simultaneously draining memories or dominating minds. It positions itself to maximize the effect of its Mucus Cloud, forcing enemies to make Constitution saves or become cursed with water dependency.

The creature's Legendary Actions allow it to maintain pressure between turns, using Lash to continue attacking or Psychic Drain to heal while damaging controlled or grappled enemies. Its Legendary Resistance ensures it can avoid critical spell effects when necessary.

In its lair, the aboleth becomes significantly more dangerous, gaining an additional use of both Legendary Resistance and Legendary Actions per round.

Encounter Ideas

The Sunken Palace: Ancient ruins beneath a lake hide an aboleth's domain. Strange dreams plague nearby villagers as the creature slowly extends its mental influence, seeking to dominate the surface world above.

The Corrupt Spring: A once-sacred spring now flows with tainted water. Those who drink from it find themselves compelled to return, eventually becoming the aboleth's willing servants.

The Deep Expedition: Explorers investigating an underground river system discover an aboleth's lair. The creature offers ancient knowledge in exchange for service, presenting a moral dilemma about the price of forbidden wisdom.

The Puppet Master: A coastal town's leadership has fallen under an aboleth's control. The creature manipulates politics and trade from the shadows, using its dominated servants to expand its influence.

Lair Features

An aboleth's lair is typically located in the deepest parts of large bodies of water - ancient lakes, underground seas, or vast flooded caverns. The lair itself reflects the creature's alien nature and vast age:

• Twisted Architecture: Structures built from materials that seem to shift and flow, defying conventional understanding of construction
• Memory Pools: Shallow basins filled with a silvery substance that contains absorbed memories from countless victims
• Dominated Servants: Various aquatic creatures and transformed surface dwellers serve as guards and laborers
• Ancient Artifacts: Relics from civilizations that existed before recorded history, some containing powerful magic
• Mucus Channels: Waterways coated with the aboleth's transformative slime, creating an environment hostile to air-breathing creatures

Treasure

Aboleths accumulate vast hoards over their millennia-long lifespans, though their alien perspective means they value items differently than most creatures:

Typical Treasure: Ancient coins and jewelry from long-dead civilizations, rare pearls and gems, magical items recovered from sunken ships or forgotten ruins.

Unique Items: Tablets inscribed with primordial knowledge, artifacts from the time before the gods, magical items that control water or minds, preserved specimens of extinct creatures.

Knowledge as Treasure: Perhaps most valuable are the secrets locked in the aboleth's memory - the locations of lost cities, the true names of ancient powers, forbidden spells, and historical events thought to be myths.

Plot Hooks

The Dreaming Sickness: A mysterious ailment causes people to dream of underwater cities and ancient knowledge. The afflicted become increasingly obsessed with finding these places, not knowing an aboleth is calling to them.

The Scholar's Bargain: A desperate researcher seeks the party's help in contacting an aboleth, believing the creature holds the key to preventing a prophesied catastrophe. The question becomes whether the cure is worse than the disease.

The Forgotten Covenant: Ancient texts speak of a pact between an aboleth and a long-dead civilization. Now something has awakened the creature, and it seeks to collect on promises made centuries ago.

The Tainted Bloodline: A noble family's ancestral connection to an aboleth grants them strange powers but also makes them vulnerable to the creature's influence. Political intrigue and body horror intertwine as the aboleth seeks to reclaim its "property."