Actions

Tentacles. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 6 (1d6+2) psychic damage. If the target is Medium or smaller, it is grappled (escape DC 12) and must succeed on a DC 12 Intelligence saving throw or be stunned until this grapple ends.
Shortbow. Ranged Weapon Attack: +6 to hit, reach 80/320 ft., one creature. Hit: 6 (1d6+2) piercing damage.
Mind Blast. The mind flayer magically emits psychic energy in a 15-feet cone. Each creature in that area must succeed on a DC 12 Intelligence Saving Throw or take 8 (2d4+2) 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.

Suggested Environments

Underdark