ILLITHID PSIONICIST or Pure Illithid – 5e stats

Medium aberration, lawful evil

Armor Class 15 (breastplate)
Hit Points 71 (13d8 + 13)
Speed 30 ft.

Proficiency Bonus +3
Proficiency Bonus +6 (5th Edition Advanced Mode)

STRDEXCONINTWISCHA
11 (+0)12 (+1)12 (+1)19 (+4)17 (+3)17 (+3)

Saving Throws lnt +7, Wis +6, Cha +6
Skills Arcana +7, Deception +6, Insight +6, Perception +6, Persuasion +6, Stealth +4
Senses darkvision 120 ft., passive perception 16
Languages Deep Speech, Undercommon, telepathy 120 ft.
Challenge 7 (2,900 XP)

Magic Resistance. The mind flayer has advantage on saving throws against spells and other magical effects.

Psionic Powers (suggested). The Illithid has 266 (13d12 + 182) PSPs and can use the following psionic powers, mental attacks and mental defenses:

ACTIONS

  • Multiattack (suggested). The mind flayer can make four attacks with its tentacles or one attack with its extract brain ability if conditions are met.
  • Tentacles (suggested). Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 2 (1d4) psychic damage. If the target is Large or smaller, it is grappled (escape DC 15) and must succeed on a DC 15 Strength saving throw or suffer automatic damage in the next round. Add +2 to the escape DC for each tentacle grappling the target. If at any moment the target is grappled by four tentacles, then the mind flayer can activate the extract brain ability as a swift action.
  • Tentacles. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 15 (2d10 + 4) psychic damage. If the target is Medium or smaller, it is grappled (escape DC 15) and must succeed on a DC 15 Intelligence saving throw or be stunned until this grapple ends.
  • Extract Brain. Melee Weapon Attack: +7 to hit, reach 5 ft., one incapacitated humanoid grappled by the mind flayer. Hit: The target takes 55 (10d10) piercing damage. If this damage reduces the target to 0 hit points, the mind flayer kills the target by extracting and devouring its brain.
  • Mind Blast (Recharge 5-6). The mind flayer magically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 15 Intelligence saving throw or take 22 (4d8 + 4) psychic damage and be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
  • Mind Blast (suggested). The mind flayer magically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 19 Intelligence saving throw or take 22 (4d8 + 4) psychic damage and be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

MIND FLAYER’s TACTICS (read the article)

5th Edition Advanced Mode
Limiting the power of a character and making the overall difficulty of the game harder, does not reduce the creativity, indeed it does quite the opposite.
The Game Master has the option to use any and all of the instances proposed in this guide, or just some of them according to their preference.

It is the lack of something that move and motivate characters, not the abundance of it

DESCRIPTION

The mind flayer, is an evil and feared creature of the Underdark; its powers are formidable and it feeds on the brains of any creature it encounters.

Using arcane powers, it enslaves or destroys its foes, which include such powerful creatures as drow and kuo-toa.

Mind Flayers stand about 6 feet tall and have hideous mauve skin that glistens with slime.

The head resembles an octopus, with white eyes (no pupils are evident) and four tentacles around its mouth, a round, many-toothed orifice like that of a lamprey.

The creature has three reddish fingers and a thumb on each hand.

Mind Flayers have darkvision. They can communicate with any creatures via innate telepathy; they have no spoken language, although they often accompany their thoughts with hissing, and the eager lashing of their tentacles.

Mind flayers dress in flowing robes, often with high, stiff collars, adorned with symbols of death and despair.

HABITAT / SOCIETY

Mind flayers hate sunlight and avoid it when possible. They live in underground cities of 2d10 x 100 mind flayers, plus at least two slaves per mind flayers.

All the slaves are under the effects of a dominate monster, and obey their illithid masters without question.

The center of a community is its elder brain, a pool of briny fluid that contains the brains of the city’s dead mind flayers. Due to the mental powers of mind flayers, the elder brain is still sentient, and the telepathic union of its brains rules the community.

The elder brain has a telepathic range of 2 to 5 miles, depending on its age and size. It does not attack, but telepathically warns the mind flayers of the presence of thinking creatures, so a mind flayer within its telepathic radius can be surprised only by non-intelligent creatures.

The range of the elder brain determines the territory claimed and defended by the community, though raiding parties are sent far beyond this limit.

Mind flayers have no family structure. Their social activities include eating, communicating with the elder brain, and debating on the best tactics to conquer the Underdark.

For amusement, they inflict pain on their captives and force slaves to fight in gladiatorial games.

Mind flayers are arrogant, viewing all other species only as cattle to be fed upon. They prefer to eat the brains of thinking creatures.

ECOLOGY

Mind flayers live between 120 and 200 years. They are warm-blooded amphibians, and spend the first 10 years of life as tadpoles, swimming in the elder-brain pool until they either die (which most do) or grow into adult mind flayers.

On an irregular basis, adult mind flayers feed brains to the tadpoles, which do not molest the elder brain. Mind flayers are hermaphroditic; each can produce one tadpole twice in its life.

Mind flayer ichor is an effective ingredient in a potion of ESP.