Armor Class 15 (natural armor)
Hit Points 85 (10d8 + 40)
Speed 30 ft., climb 30 ft.
Saving Throws DEX +7, INT +0, WIS +5, CHA +7
Skills Perception +5, Stealth +7
Damage Resistances necrotic, psychic
Condition Immunities charmed, exhaustion, frightened
Senses darkvision 120 ft., passive Perception 15
Languages telepathy 120 ft. but can only project emotions
Challenge 5
Spider Climb. The mind flayer can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Sunlight Sensitivity. While in sunlight, the mind flayer has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
Unusual Nature. The mind flayer doesn't require air, food, or sleep.
Multiattack. The mind flayer makes two Claw attacks or one Claw attack and one Tentacles attack.
Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage plus 10 (3d6) necrotic damage.
Tentacles. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 7 (1d6 + 4) piercing damage, and if the target is a creature, it is grappled (escape DC 15).
Drink Sapience. The mind flayer targets one creature it is grappling. The target must succeed on a DC 15 Wisdom saving throw or take 14 (4d6) psychic damage and gain 1 level of exhaustion. The mind flayer regains a number of hit points equal to the psychic damage dealt. A creature reduced to 0 hit points by the psychic damage dies.
Disrupt Psyche (Recharge 5–6). The mind flayer magically emits psionic energy in a 30-foot-radius sphere centered on itself. Each creature in that area must succeed on a DC 15 Intelligence saving throw or be incapacitated for 1 minute. The incapacitated creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
VRGR, p. 252