Data Drainer

Detect Sentience. The data drainer can sense the presence and location of any creature within 300 feet of it that has an Intelligence of 3 or higher, regardless of interposing barriers, unless the creature is protected by a mind blank spell.

Innate Spellcasting. The data drainer’s innate spellcasting ability is Intelligence (spell save DC 14). It can innately cast the following spells, requiring no somatic, material or verbal components:
At-will: hold person

Multiattack. The data drainer makes two attacks with its tentacles and uses Devour Data. The scyphozoa may also forego both of its tentacle attacks and make one attack with its proboscis instead.

Tentacles. Melee Weapon Attack: +6 to hit, reach 10 ft., one creature. Hit:  9 (1d10 + 3) piercing damage and the target must succeed on a DC 13 Constitution saving throw or be poisoned for 1 minute. The poisoned target is paralyzed, and it can repeat the saving throw at the end of each of its turns, ending the effect on a success.

The target is also grappled (escape DC 15). If the target is Medium or smaller, it is also restrained until this grapple ends. While grappling the target, the data drainer has advantage on attack rolls against it and can’t use this attack against other targets. When the data drainer moves, any Medium or smaller target it is grappling moves with it.

Proboscis. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 11 (2d6 + 3) piercing damage.

Devour Data. The data drainer targets one incapacitated creature it can see within 10 feet of it that has an Intelligence of at least 3. The target must succeed on a DC 13 Intelligence saving throw against this magic or take 11 (2d10) psychic damage. Also on a failure, roll 3d6: If the total equals or exceeds the target’s Intelligence score, that score is reduced to 0. The target is stunned until it regains at least one point of Intelligence.