Amphibious.

The morkoth can breathe air and water.

Actions

Multiattack.

The morkoth makes either two Bite attacks and one Tentacles attack or three Bite attacks.

Bite.

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) slashing damage plus 10 (3d6) psychic damage.

Tentacles.

Melee Weapon Attack: +6 to hit, reach 15 ft., one target. Hit: 15 (3d8 + 2) bludgeoning damage, and the target is grappled (escape DC 14) if it is a Large or smaller creature. Until this grapple ends, the target is restrained and takes 15 (3d8 + 2) bludgeoning damage at the start of each of its turns, and the morkoth can't use its tentacles on another target.

Hypnosis.

The morkoth projects a 30-foot cone of magical energy. Each creature in that area must make a DC 17 Wisdom saving throw. On a failed save, the creature is charmed by the morkoth for 1 minute. While charmed in this way, the target tries to get as close to the morkoth as possible, using its actions to Dash until it is within 5 feet of the morkoth. A charmed target can repeat the saving throw at the end of each of its turns and whenever it takes damage, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature has advantage on saving throws against the morkoth's Hypnosis for 24 hours.

Spellcasting.

The morkoth casts one of the following spells, requiring no material components and using Intelligence as the spellcasting ability (spell save DC 17):

At will: detect magic, mage hand
3/day each: darkness, dimension door, dispel magic, lightning bolt, sending

Reactions

Spell Reflection.

If the morkoth makes a successful saving throw against a spell or a spell attack misses it, the morkoth can choose another creature (including the spellcaster) it can see within 120 feet of it. The spell targets the chosen creature instead of the morkoth. If the spell forced a saving throw, the chosen creature makes its own save. If the spell was an attack, the attack roll is rerolled against the chosen creature.

Lair Actions

On initiative count 20 (losing initiative ties), the morkoth can take one of the following lair actions:

Cast a Spell. The morkoth casts darkness, dispel magic, or misty step, using Intelligence as its spellcasting ability and without expending a spell slot.
Hypnotize. The morkoth uses its Hypnosis action, originating at a point within 120 feet of itself. It doesn't need to see the effect's point of origin.

Regional Effects

The island surrounding a morkoth's lair is warped by the creature's presence, creating the following effects:

Alter Water. With a thought (no action required), the morkoth can initiate a change in the water within its lair that takes effect 1 minute later. The water can be as breathable and clear as air, or it can be normal water (ranging in clarity from murky to clear).
Locate Creatures and Objects. The morkoth is aware of any new arrival, whether an object or a creature, on its island or in its sanctum. As an action, the morkoth can locate any one creature or object on the island. Visitors to the island feel as though they are being watched, even when they aren't.
Lost Possessions. Each time a creature that has been on the island for less than a year finishes a short or long rest, it must make a DC 10 Intelligence saving throw. On a failure, the creature has misplaced one possession (chosen by the player, if the creature is that player's character). The possession remains nearby but concealed for a short time, so it can be recovered with a successful DC 15 Wisdom (Perception) check. An object that is misplaced but not recovered ends up in the morkoth's lair 1 hour later. If the creature later goes to the morkoth's lair, its lost possessions stand out in its perception and are easily recovered.
Supernatural Lure. Entrances to the morkoth's lair have an enchantment that the morkoth can activate or suppress at any time while it's in its lair and not incapacitated. Any creature within 30 feet of such an entrance and able to see it must make a DC 15 Wisdom saving throw. On a failed save, the creature feels an intense urge to use its movement on each of its turns to enter the lair and to move toward the morkoth's location (the target doesn't realize it's heading toward a creature). The target moves toward the morkoth by the most direct route. As soon as it can see the morkoth, the target can repeat the saving throw, ending the effect on itself on a success. It can also repeat the saving throw at the end of each of its turns and every time it takes damage.

If the morkoth dies, these regional effects end immediately.

Environment: Coastal, Underwater

Morkoth