Medium aberration, lawful evil

Armor Class 15 (breastplate)

Hit Points 71 (13d8+13)

Speed 30 ft.

STR DEX CON INT WIS CHA
11 (0) 12 (+1) 12 (+1) 19 (+4) 17 (+3) 17 (+3)

Saving Throws Int +7, Wis +6, Cha +6

Skills Arcana +7, Deception +6, Insight +6, Perception +6, Persuasion +6, Stealth +4

Senses darkvision 120 ft.

Languages Deep Speech, Undercommon, telepathy 120 ft.

Challenge 8 (3,900 XP)

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

Innate Spellcasting (Psionics). The mind flayer’s innate spellcasting ability is Intelligence (spell save DC 15). It can innately cast the following spells, requiring no components:

At will: detect thoughts, levitate

1/day each: dominate monster, plane shift (self only)

Spellcasting. The mind flayer is a 10th-level spellcaster. Its spellcasting ability is Intelligence (save DC 15, +7 to hit with spell attacks). The mind flayer has the following wizard spells prepared:

  • Cantrips (at will): blade ward, dancing lights, mage hand, shocking grasp

  • 1st level (4 slots): detect magic, disguise self, shield, sleep

  • 2nd level (3 slots): blur, invisibility, ray of enfeeblement

  • 3rd level (3 slots): clairvoyance, lightning bolt, sending

  • 4th level (3 slots): confusion, hallucinatory terrain

  • 5th level (2 slots): telekinesis, wall of force

Actions

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.