A Guide to Aberrations in DnD 5e

Unnatural alien beings

Many believe that aberrations all come from the Far Realm, a realm of madness at the edges of the cosmos that transforms unsuspecting visitors into malformed creatures (aberrations). While it is true that many aberrations seem to come from the Far Realm, it also seems that other aberrations come from other circumstances.

Beholders, for example, were created as spies by the gods of other realms before becoming cursed into their current state, aboleths pre-date the creation of the known universe and mind flayers seem to come from a time period in the future. Generally though, aberrations can be considered as creatures that appear alien in form, though this obviously encompasses a vast array of forms and types.

The challenge with fully defining aberrations is that unlike other groups of creatures in the D&D universe, they do not have an origin or abilities that are similar or linked to one another. Their main distinction is that they are creatures that don’t seem to belong in the natural order of the material realm or even any known plane.

About aberrations

Despite their differences, many aberrations do share a few abilities in common such as the use of darkvision or the ability to use psychic powers. Even the study of aberrations is fraught with danger though as someone studying about them can be drastically affected by such study.

True knowledge of aberrations requires learning their symbology and concepts, which are so unlike humanoid concepts. Learning such things can even drive a person to insanity.

Humanoids and other creatures can also find themselves turned into an aberration; for example, a mind flayer can turn humanoids into other mind flayers through a process known as ceremorphosis, Star spawn can be created by those making contact with the elder evils and those entering the Far Realm, are often transformed into aberrations of many types and forms.

Types of Aberrations


Beholder lair

Highly intelligent creatures that look like floating heads with a large central eye and eye stalks protruding from its head. Each eye stalk is a powerful weapon that attacks with different and devastating powers. Beholders tend to be paranoid creatures, whether that’s of members of their own kind or other creatures and will generally act with aggression. Occasionally, beholders do integrate themselves into the societies of other creatures like the Xanathar, but this is unusual and more often, beholders will seek to maim or subjugate.

Types of beholders

  • Beholder (CR 13) – MM: The standard variety of beholder
  • Death Kiss (CR 10) – MotM: Lesser beholders born from the nightmares of beholders. Instead of eyestalks, they have tentacles , each ending in a mouth full of teeth.
  • Gauth (CR 6) – MotM: Lesser beholders that appear smaller and often enter the material plane when a spectator summoning doesn’t work. Gauths must consume magical items to maintain their presence on the material plane.
  • Gazer (CR 1/2) – MotM: Born into existence by a true beholder, gazer’s are tolerated by beholders who view them like a pet more than anything else.
  • Spectator (CR 3) – MM: A lesser beholder summoned from another plane to protect items of great value.

In addition, a few other beholder varieties known as beholder zombies and death tyrants are undead variants of beholders while a mind witness is a beholder that has undergone ceremorphosis to become a mind flayer variant.

Mind flayers

Mind flayers (also known as illithid) are alien looking humanoids with tentacles covering their mouth. They are psionic creatures that operate in a hive, telepathically linked to one another and typically ruled by a central hive mind known as an elder brain.

Mind flayers are evil creatures that seek to enslave other creatures through mind control. They are able to create new mind flayers from their captives through a process called ceremorphosis where mind flayer tadpoles are inserted into the brain of a host where it gradually transforms the host into a mind flayer.

Mind flayer types

  • Cranium Rat (CR 0) – MotM: Created when mind flayers bombard rats with psionic energy, these creatures become more intelligent than ordinary rats.
  • Swarm of Cranium Rats (CR 5) – MotM: Cranium rats that gather in a swarm merge their minds to become a shared intellect.
  • Elder Brain (CR 14) – MotM: A large psychic brain that acts as the hive mind of mind flayer colonies.
  • Mind Flayer (CR 7) – MM: The standard variety of mind flayer.
  • Mind Witness (CR 5) – MotM: Beholders that have undergone ceremorphosis become mind witnesses. A combination of beholder and mind flayer.
  • Neothelid (CR 13) – MotM: If an elder brain dies, the mind flayer tadpoles may be left to fend for themselves. Eventually, they will eat one another until only one tadpole is left. This tadpole becomes a neothelid; a huge, predatory, worm-like creature
  • Ulitharid (CR 9) – MotM: A powerful form of mind flayer that sometimes lead colonies of mind flayers without an elder brain. When an ulitharid dies, it transforms into an elder brain.

In addition to these types of mind flayers are undead mind flayers known as vampiric mind flayers and alhoons. Vampiric mind flayers have undergone vampirism to achieve immortality while alhoons have become liches to achieve similar results.


Neogi 5e

These spider-like creatures left their own realm long ago to conquer and consume creatures in other realms. They now dwell in the far corners of the material plane as well as the astral and ethereal planes.

Neogi use mind control, with stronger neogi controlling the minds of weaker neogi. For these creatures, the idea that an individual might want to exert their own will is a foreign concept. For them, the strong control the weak and they understand no other way.

Neogi tyypes

  • Neogi Hatchling (CR 1/8) – (MotM): When a neogi becomes old and is no longer useful, it is overpowered and injected with poison, turning its body into a bloated mass, ideal for incubating neogi eggs. Neogi eggs then hatch from this flesh, consuming it and one another until only a few of the strongest neogi survive who are able to live to maturity.
  • Neogi (CR 3) – MotM: The standard form of neogi.
  • Neogi Master (CR 4) – MotM: Neogi masters use magic granted them of greater aberrations to aid in exacting their will and dominance over other creatures.


Accidental creations from the chaos of Limbo, slaadi are toad-like beings that respect strength and power only. They abhor order and seek to destroy all semblance of order and bring chaos to all around them.

Slaadi types

  • Blue Slaad (CR 7) – MM: These slaad have hooked claws that can scratch their victims, infecting them with a disease that transforms them into a slaad.
  • Death Slaad (CR 10) – MM: The strongest of the slaadi, death slaads rule mobs of slaadi, taking great pleasure in causing suffering.
  • Gray Slaad (CR 9) – MM: Extensions of the will of their masters, the death slaad, grey slaads perform missions on the mortal plane, hiding their appearance with their shapechanging abilitiy.
  • Green Slaad (CR 8) – MM: Intelligent slaadi capable of casting spells and shapechanging.
  • Red Slaad (CR 5) – MM: Red slaads inject eggs into their victims, using the host as a living incubator untilt he slaad tadpole is ready to burst out of the host and eat its corpse.
  • Slaad Tadpole (CR 1/8) – MM: Infant slaadi that incubate in a host before wripping out of the body and consuming the corpse.

Star spawn

Star Spawn Larva Mage 5e

Beyond the known planes are alien realms filled with unspeakable horrors. These elder evils often seek to invade the mortal planes, but are prevented from doing so. Instead, they must send servants and soldiers, transformed into forms that can journey to the material plane. These servants are known as star spawn.

Star spawn types

  • Lesser Star Spawn Emissary – VRGR: A shape changing form that star spawn emissaries can use for infiltration in the mortal realm. It can appear in any form it likes, though its true form is a writhing mass of flesh and organs. If killed, it will transform into its greater form.
  • Greater Star Spawn Emissary – VRGR: In its greater form, a star spawn emissary removes any pretence of mortality, becoming a destructive titan of violent flesh.
  • Star Spawn Grue – MotM: The weakest of the star spawn soldiers, these chittering, spiked creatures produce discordant, psychic energy.
  • Star Spawn Hulk – MotM: Large, brutish creatures with too many teeth and not enough nose, they typically follow the orders of some form of commander.
  • Star Spawn Larva Mage – MotM: A humanoid spellcaster that has contacted the far realm and had it’s body and mind merged with a star spawn. None of the mind or personality is left of the humanoid however, despite its appearance, these creatures are now, wholly star spawn.
  • Star Spawn Mangler – MotM: Hunched, gangly creatures with 6 arms that operate in the shadows as guards and assassins.
  • Star Spawn Seer – MotM: Once the leader of a cult that has contacted the elder evils, seers have been taken over by a star spawn who leads the star spawn forces in the material plane.

Other aberrations

Aboleth 5e
  • Aboleth (CR 10) – MM: Ancient, acquatic creatures that pre-date the gods. They have powerful psionic abilities and flawless memories.
  • Balhanoth (CR 11) – MotM: Creatures native to the Shadowfell that can warp reality around themselves to make their lair appear welcoming. Once ensnared, the balhanoth will take its prey and teleport it away to feed on their fear..
  • Berbalang (CR 2) – MotM: Secret gatherers that live on the husks of dead gods in the astral plane and speak to the dead to gather information.
  • Choker (CR 1) – MotM: Gangly creatures that feed on corpses and set ambushes for un wary travelers.
  • Chuul (CR 4) – MM: Large crustaceans granted sentience eons ago, they are some of the few survivors of the aboleth empire.
  • Cloaker (CR 8) – MM: Stealthy predators that look like sting rays but lurk in dark caverns, waiting to ambush their prey.
  • Derro (CR 1/4) – MotM: Dwarf-kin that prey on those weaker than themselves and give obeisance to those more powerful. They are weak on their own, but form a terrifying mob when in a group.
  • Derro Savant (CR 3) – MotM: Sorcerous derro gifted with magical powers.
  • False Hydra – Homebrew: Multi-headed abominations that are not related to hydras, instead, they feed on flesh and wipe all memory of their presence from those that might spot them.
  • Flumph (CR 1/8) – MM: Highly intelligent creatures that float around the underdark. They use telepathy to sense the attitudes of those enarby, seeking those with good hearts and fleeing those that are evil.
  • Gibbering Mouther (CR 2) – MM: Created from the victims of foul sorcery, gibbering mouthers are the combined body mass of such individuals with multiple mouths and eyes. Such a horrendous process turns these victims into this depraved and insane monster.
  • Grell (CR 3) – MM: Floating creatures with appearance of brains with a beak and sharp tentacles. They use keen hearing to sense their prey, typically operating alone.
  • Morkoth (CR 11) – MotM: Originally from the astral plane, these tentacled aliens travel the planes on mobile islands. Morkoths are born from the flesh of dead gods.
  • Nothic (CR 2) – MM: Formerly wizards that sought arcane secrets too great for them to handle, such beings become nothics using their large, central eye to rot the flesh from their enemies.
  • Otyugh (CR 5) – MM: Grotesque creatures with 3 legs and tentacles, otyughs feast on just about anythingand are quite content to consume waste and carrion.

Thinking of including something other than undead in your campaign? We’ve got you covered. Below are our guides for all the different monster types in D&D 5e:

ConstructsFeyPlant Creatures

Published by DM Ben

Ben is an experienced dungeon master and player who's been immersed in the D&D universe since he was a teenager over 20 years ago. When he's not writing for Dungeon Mister, Ben loves creating fiendish puzzles and devious dungeons for his players. He's an especially big fan of the Ravenloft and Dragonlance settings.

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