Probing Telepathy. If a creature communicates telepathically with Chickthulu, he learns the creature's greatest desires if Chickthulu can see the creature.
Legendary Resistance (3/Day). If Chickthulu fails a saving throw, he can choose to succeed instead.
Magic Resistance. Chickthulu has advantage on saving throws against spells and other magical effects.
Magic Weapons. Chickthulu’s weapon attacks are magical.
Multiattack. Chickthulu makes three tentacle attacks.
Tentacle. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) bludgeoning damage. If the target is a creature, it must succeed on a DC 14 Constitution saving throw or become grappled.
Talon. Melee Weapon Attack: +9 to hit, reach 10 ft. one target. Hit: 15 (3d6 + 5) slashing damage.
Enslave (3/Day). Chickthulu targets one creature it can see within 30 feet of it. The target must succeed on a DC 14 Wisdom saving throw or be magically charmed by Chickthulu until Chickthulu dies or until it is on a different plane of existence from the target. The charmed target is under Chickthulu control and can't take reactions, and Chickthulu and the target can communicate telepathically with each other over any distance.
Whenever the charmed target takes damage, the target can repeat the saving throw. On a success, the effect ends. No more than once every 24 hours, the target can also repeat the saving throw when it is at least 1 mile away from Chickthulu.
Chickthulu can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Chickthulu regains spent legendary actions at the start of its turn.
Detect. Chickthulu makes a Wisdom (Perception) check.
Tentacle. Chickthulu makes one tentacle attack.
Psychic Drain (Costs 2 Actions). One creature charmed by Chickthulu takes 10 (3d6) psychic damage, and Chickthulu regains hit points equal to the damage the creature takes.