Adult // Elder Oblex 5e: Stats & Guide For Players and DMs

Last Updated on October 25, 2022

ADULT OBLEX STAT BLOCK


Adult Oblex

medium Ooze Lawful Evil

Armor Class:

14

Hit Points:

75 (10d8+30)

Speed:

20 feet

STR

8 (-1)

DEX

19 (+4)

CON

14 (+2)

INT

17 (+3)

WIS

12 (+1)

CHA

17 (+3)

Saving Throws:

Int +7, Cha +5

Skills:

Deception +5, Perception +4, one of Arcana/History/Nature/Religion +7

Condition Immunities:

Blinded, charmed, deafened, exhaustion, prone

Senses:

Blindsight 60 feet (blind beyond this distance), passive Perception 14

Languages:

Common (Plus Two More)

Challenge:

5 (1,800 XP)

Amorphous:

The Oblex can move through a narrow space of up to 1 inch without squeezing.



Aversion to Fire:

If the Oblex takes fire damage, it has disadvantage on attack rolls and ability checks for a turn.



Innate Spellcasting:

The Oblex can cast charm person (as a 5th-level spell), color spray, detect thoughts, and hold person (as a 3rd-level spell) three times a day each (spell save DC 15).



Sulfurous Impersonation:

The Oblex can extend a portion of itself to create a simulacrum of a creature whose memories it has devoured. That creature smells faintly of sulfur but otherwise looks and feels as it should. The oblex can impersonate 1d4+1 different creatures and is treated as being in the same space as the simulacrum and its own space.



Actions

Multiattack:

The Oblex makes one attack with its pseudopod and uses its Eat Memories ability.



Pseudopod:

+7 to hit, 5 foot reach, one target. Hit. 1d6+4 (7) bludgeoning damage plus 2d4 (5) psychic damage.



Eat Memories:

The Oblex forces a DC 15 Wisdom save against an adjacent creature for 4d8 (18) psychic damage and becomes memory drained, subtracting a d4 from its abilities checks and attack rolls until it finishes a rest or receives healing or restoration. This die increases the more drained a target gets until they fall unconscious. An Oblex gains all proficiencies of a creature it has memory drained, except for its saving throws.




The illithids are a conniving lot, happy to experiment on all sorts of creatures in an attempt to further their goals and hunger.

While many players know about the intellect devourer and the elder brain, few know of another creature created by these outsiders: the oblex. 

But, what is an oblex? What unique features does an oblex have that make it a foe to take seriously?

Let’s take a look at what makes up an oblex and how both players and DMs can be prepared for the use of this strange creature. 

What Are Oblexes?

An oblex is an experiment created by the illithid, the mind flayers that haunt the corners of society and the Underdark.

These oozes possess the ability to mentally assault their victims, sapping their memories and capabilities with their psionic capabilities.

Even more devious, an oblex can create a simulacrum of a creature whose mind it has absorbed to lure further victims into its grasp. 

Oblexes come in three forms: an oblex spawn, an adult oblex, and the elder oblex. Here’s the statblock for the adult oblex: 

Adult Oblex

Medium ooze, lawful evil

Armor Class: 14

Hit Points: 75 (10d8+30)

Speed: 20 feet

STR 8, DEX 19, CON 16, INT 19, WIS 12, CHA 15

Saving Throws: Int +7, Cha +5

Skills: Deception +5, Perception +4, one of Arcana/History/Nature/Religion +7

Condition Immunities: Blinded, charmed, deafened, exhaustion, prone

Senses: Blindsight 60 feet (blind beyond this distance), passive Perception 14

Languages: Common plus two more

Challenge Rating: 5 (1,800 XP)

Amorphous. The oblex can move through a narrow space of up to 1 inch without squeezing. 

Aversion to Fire. If the oblex takes fire damage, it has disadvantage on attack rolls and ability checks for a turn. 

Innate Spellcasting. The oblex can cast charm person (as a 5th-level spell), color spray, detect thoughts, and hold person (as a 3rd-level spell) three times a day each (spell save DC 15). 

Sulfurous Impersonation. The oblex can extend a portion of itself to create a simulacrum of a creature whose memories it has devoured. That creature smells faintly of sulfur but otherwise looks and feels as it should. The oblex can impersonate 1d4+1 different creatures and is treated as being in the same space as the simulacrum and its own space. 

Multiattack. The oblex makes one attack with its pseudopod and uses its Eat Memories ability. 

Pseudopod. +7 to hit, 5 foot reach, one target. Hit. 1d6+4 (7) bludgeoning damage plus 2d4 (5) psychic damage.

Eat Memories. The oblex forces a DC 15 Wisdom save against an adjacent creature for 4d8 (18) psychic damage and becomes memory drained, subtracting a d4 from its abilities checks and attack rolls until it finishes a rest or receives healing or restoration. This die increases the more drained a target gets until they fall unconscious. 

An oblex gains all proficiencies of a creature it has memory drained, except for its saving throws.

As a comparison, here is the statblock for the more powerful elder oblex: 

Elder Oblex

Huge ooze, lawful evil

Armor Class: 16

Hit Points: 115 (10d12+50)

Speed: 20 feet

STR 15, DEX 16, CON 21, INT 22, WIS 13, CHA 18

Saving Throws: Int +10, Cha +8

Skills: Arcana +10, Deception +8, History +10, Nature +10, Perception +4, Religion +10

Condition Immunities: Blinded, charmed, deafened, exhaustion, prone

Senses: Blindsight 60 feet (blind beyond this distance), passive Perception 15

Languages: Common plus six more

Challenge Rating: 10 (5,900 XP)

Amorphous. The elder oblex can move through a narrow space of up to 1 inch without squeezing. 

Aversion to Fire. If the elder oblex takes fire damage, it has disadvantage on attack rolls and ability checks for a turn. 

Innate Spellcasting. The elder oblex can cast charm person (as a 5th-level spell), detect thoughts, and hold person at-will, as well as confusion, dimension door, dominate person, fear, hallucinatory terrain, hold monster, hypnotic pattern, and telekinesis three times a day each (spell save DC 18). 

Sulfurous Impersonation. The elder oblex can extend a portion of itself to create a simulacrum of a creature whose memories it has devoured. That creature smells faintly of sulfur but otherwise looks and feels as it should. The oblex can impersonate 2d6+1 different creatures, and it is treated as being in the same space as the simulacrum and its own space. 

Multiattack. The elder oblex makes two pseudopod attacks and uses its Eat Memories ability. 

Pseudopod. +7 to hit, 10 foot reach, one target. Hit. 4d6+3 (17) bludgeoning damage plus 2d6 (7) psychic damage.

Eat Memories. The elder oblex forces a DC 18 Wisdom save against an adjacent creature for 8d10 (44) psychic damage and becomes memory drained, subtracting a d4 from its abilities checks and attack rolls until it finishes a rest or receives healing or restoration. This die increases the more drained a target gets until they fall unconscious. 

An elder oblex gains all proficiencies of a creature it has memory drained, except for its saving throws. 

While the two statblocks don’t differ too much in their capabilities, the features of the oblexes make it clear that this creature is different from the standard ooze.

Rather than mindlessly hunting for its prey, the oblex uses deception and cunning to lure its prey into grasp. The simulacrum and spells that the oblex has at its disposal allow for mind-affecting spells and lies to take root. 

From there, the oblex uses its pseudopods to bludgeon its foes into submission once their prey is cornered.

These pseudopods assault both the mind and body, dealing both bludgeoning and psychic damage, making these attacks harmful to even a raging barbarian. 

Whether it is skulking towards or away from its target, an oblex can squeeze itself down between the cracks of floorboards or the bars of a prison window despite its large size. 

With all of these features combined, the oblex makes for a deadly threat. 

How To Fight an Oblex

While an oblex will be a new challenge for many D&D players, the creature does have some weaknesses that can be exploited.

If you and your adventuring party can capitalize on one or more of those weaknesses, you’ll succeed in a fight against this creature. 

The most obvious weakness of the oblex is its Aversion to Fire feature. With this feature, an oblex has disadvantage on both attack rolls and ability checks for a round when exposed to fire damage.

If you have a character that can reliably dish out flames, such as a caster with the firebolt cantrip, you can keep the oblex’s offensive options limited. 

Also, many of the spells that you see on the adult and elder oblex’s statblock are best used outside of combat.

Spells like charm person, hallucinatory terrain, and detect thoughts help the oblex understand and deceive their prey, but they don’t help when said prey fights back.

The elder version of the oblex has plenty of spells that can obstruct and disorient adventurers, so watch out. 

Finally, both versions of the oblex have mediocre hit points and AC for their challenge rating and plenty of weak saving throws to target.

Strength, Constitution, and Wisdom all make for good saves to target with your spells and abilities in combat against an oblex, while Intelligence and Charisma tend to be high saves for these creatures.

How Should A DM Run an Oblex Encounter?

A clever DM won’t throw an oblex against a party in a head-on encounter. Instead, a DM will use an oblex to deceive the players into a poor position before striking at them.

Much like its creators, an oblex prefers to use tricks to ambush its prey. 

Because of the simulacra that an oblex can create, a DM has to think carefully about how they use that feature.

These simulacra have a thin strand that traces back to the oblex, meaning that the oblex can’t just send out a simulacrum without the party noticing the strand.

Instead, a creative DM will find ways to obscure these strands to the simulacra from the players to keep them from noticing that something is up. 

Finally, DMs will try to take advantage of the oblex’s spells to have the creature learn more about the players.

With the charm and mind-reading spells available to the oblex, this creature can do a lot of legwork on the party before striking. 

Oblex Encounter Ideas

While many DMs love the idea of running an encounter using an oblex, their use isn’t very common.

To get the creative juices flowing, here are some example encounters a DM might create that feature an oblex opponent: 

  • An oblex uses simulacra to lure people into an abandoned house, the sulfurous strands hidden inside the gaps of the old floorboards. 
  • When the party walks underneath a grated ceiling, an elder oblex begins casting area spells, like hypnotic pattern and fear, to ambush and trap the players. 
  • Using hallucinatory terrain, an elder oblex hides inside of a central location in a dungeon while using its simulacra as guards. This elder oblex acts as the watchdog for an illithid community, eating the memories of a creature before the illithids eat the brain.  

The oblex is best used when their cunning capabilities allow them to maximize their ambush potential.

Also, with how intelligent these oozes are, it makes sense to pair them up with other intelligent monsters or use less intelligent monsters as part of their strategy to lure in prey. 

Oblex FAQs

Because the oblex is a more obscure creature in D&D lore, it doesn’t see as much use as other iconic creatures.

Because of that fact, here are some answers to the common questions people have about oblexes in D&D 5e

What Is An Oblex?

An oblex is an ooze that is the result of many experiments by the illithid, resulting in the creation of a psionic, intelligent ooze that can absorb memories and trick unwitting prey. 

What Book(s) Are Oblexes Found In?

All the statblocks for the oblex can be found in Mordenkainen’s Tome of Foes

How Smart Is an Oblex?

The Intelligence score of an oblex depends on how old the creature is. An oblex spawn has an Intelligence of 14, while the adult oblex and elder oblex have an Intelligence of 19 and 22, respectively. 

Summary

The oblex is an interesting creature thanks to the deceptive abilities and psionic spells that it can use to manipulate and trick foes.

Combined with some decent attacks and an ability to absorb memories, and the oblex makes for an interesting encounter that your party won’t forget as long as you can create an environment where the oblex can use its full repertoire of spells and abilities.