Amphibious. The tarrakolichithidholder can breathe air and water.

Antimagic Cone. The tarrakolichithidholder's central eye creates an area of antimagic, as in the antimagic field spell, in a 150-foot-cone. At the start of each of its turns, the tarrakolichithidholder decides which way the cone faces and whether the cone is active. The area works against the tarrakolichithidholder's own eye rays.

Freedom of Movement. The tarrakolichithidholderithid ignores difficult terrain, and magical effects can't reduce its speed. It can spend 5 feet of movement to escape from nonmagical restraints or being grappled.

Innate Spellcasting (Psionics). The tarrakolichithidholderithid's innate spellcasting ability is Intelligence (spell save DC 15). It can innately cast the following spells, requiring no components:

At will: detect thoughts, levitate

Magic Resistance. The tarrakolichithidholderithid has advantage on saving throws against spells and other magical effects.

Siege Monster. The tarrakolichithidholderithid deals double damage to objects and structures.

Reflective Carapace. Any time the tarrakolichithidholder is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, the tarrakolichithidholder is unaffected. On a 6, the tarrakolichithidholder is unaffected, and the effect is reflected back at the caster as though it originated from the tarrakolichithidholder, turning the caster into the target.

Rejuvenation. If it has a phylactery, a destroyed tarrakolichithidholder gains a new body in 1d10 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the phylactery.

Spellcasting. The tarrakolichithidholder is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). The lich has the following wizard spells prepared:

Cantrips (at will): mage hand, prestidigitation, ray of frost

1st level (4 slots): detect magic, magic missile, shield, thunderwave

2nd level (3 slots): acid arrow, calm emotions, invisibility, shatter

3rd level (3 slots): animate dead, counterspell, dispel magic, lightning bolt

4th level (3 slots): blight, dimension door

5th level (3 slots): cloudkill, scrying

6th level (1 slot): disintegrate, globe of invulnerability

7th level (1 slot): finger of death, plane shift

8th level (1 slot): dominate monster, power word stun

9th level (1 slot): power word kill

Turn Resistance. The tarrakolichithidholder has advantage on saving throws against any effect that turns undead.

Multiattack. The tarrakolichithidholder uses its frightfull presence and then makes seven attacks: one with it's bite, two with it's claws, one with its horns, and three with its tentacles, each of which it can replace with one use of Fling.

Bite. Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 23 (3d8 + 10) piercing damage. If the target is a Large or smaller creature grappled by the tarrakolichithidholder, that creature is swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside the tarrakolichithidholder, and it takes 42 (12d6) acid damage at the start of each of the tarrakolichithidholder's turns.

If the tarrakolichithidholder takes 50 damage or more on a single turn from a creature inside it, the tarrakolichithidholder must succeed on a DC 25 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the tarrakolichithidholder. If the tarrakolichithidholder dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 15 feet of movement, exiting prone.

Claw. Melee Weapon Attack: +18 to hit, reach 15ft., one target. Hit: 28 (4d8 + 10) slashing damage.

Horns. Melee Weapon Attack: +18 to hit, reach 10ft., one target. Hit: 32 (4d10 + 10) piercing damage.

Tentacle. Melee Weapon Attack: +18 to hit, reach 30 ft., one target. Hit: 20 (3d6 + 10) bludgeoning damage, and the target is grappled (escape DC 18) and must succeed on a DC 18 Intelligence saving throw or be stunned until this grapple ends. The tarrakolichithidholderithid has ten tentacles, each of which can grapple one target.

Extract Brain. Melee Weapon Attack: +7 to hit, reach 5 ft., one incapacitated humanoid grappled by the tarrakolichithidholder. Hit: The target takes 55 (10d10) piercing damage. If this damage reduces the target to 0 hit points, the tarrakolichithidholder kills the target by extracting and devouring its brain.

Fling. One Large or smaller object held or creature grappled by the tarrakolichithidholder is thrown up to 60 feet in a random direction and knocked prone. If a thrown target strikes a solid surface, the target takes 3 (1d6) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 18 Dexterity saving throw or take the same damage and be knocked prone.

Frightful Presence. Each creature of the tarrakolichithidholder choice within 120 feet of it and aware of it must succeed on a DC 18 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if the tarrakolichithidholder is within line of sight, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the tarrakolichithidholderithid's Frightful Presence for the next 24 hours.

Eye Rays. The tarrakolichithidholderholder shoots three of the following magical eye rays at random (reroll duplicates), choosing one to three targets it can see within 120 feet of it:

1. Charm Ray. The targeted creature must succeed on a DC 16 Wisdom saving throw or be charmed by the tarrakolichithidholderholder for 1 hour, or until the tarrakolichithidholderholder harms the creature.
2. Paralyzing Ray. The targeted creature must succeed on a DC 16 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
3. Fear Ray. The targeted creature must succeed on a DC 16 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
4. Slowing Ray. The targeted creature must succeed on a DC 16 Dexterity saving throw. On a failed save, the target’s speed is halved for 1 minute. In addition, the creature can’t take reactions, and it can take either an action or a bonus action on its turn, not both. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
5. Enervation Ray. The targeted creature must make a DC 16 Constitution saving throw, taking 36 (8d8) necrotic damage on a failed save, or half as much damage on a successful one.
6. Telekinetic Ray. If the target is a creature, it must succeed on a DC 16 Strength saving throw or the tarrakolichithidholderholder moves it up to 30 feet in any direction. It is restrained by the ray’s telekinetic grip until the start of the tarrakolichithidholderholder’s next turn or until the tarrakolichithidholderholder is incapacitated.
   If the target is an object weighing 300 pounds or less that isn’t being worn or carried, it is moved up to 30 feet in any direction. The tarrakolichithidholderholder can also exert fine control on objects with this ray, such as manipulating a simple tool or opening a door or a container.
7. Sleep Ray. The targeted creature must succeed on a DC 16 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target awakens if it takes damage or another creature takes an action to wake it. This ray has no effect on constructs and undead.
8. Petrification Ray. The targeted creature must make a DC 16 Dexterity saving throw. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restorations pell or other magic.
9. Disintegration Ray. If the target is a creature, it must succeed on a DC 16 Dexterity saving throw or take 45 (10d8) force damage. If this damage reduces the creature to 0 hit points, its body becomes a pile of fine gray dust.
   If the target is a Large or smaller nonmagical object or creation of magical force, it is disintegrated without a saving throw. If the target is a Huge or larger object or creation of magical force, this ray disintegrates a 10-foot cube of it.
10. Death Ray. The targeted creature must succeed on a DC 16 Dexterity saving throw or take 55 (10d10) necrotic damage. The target dies if the ray reduces it to 0 hit points.

Lightning Storm. The tarrakolicjh magically creates three bolts of lightning, each of which can strike a target the tarrakolichithidholder can see within 120 feet of it. A target must make a DC 23 Dexterity saving throw, taking 22 (4d10) lightning damage on a failed save, or half as much damage on a successful one.

The tarrakolichithidholder 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. The tarrakolichithidholder regains spent legendary actions at the start of its turn.

Attack or Fling. The tarrakolichithidholder makes one bite or tentacle attack or uses its Fling.

Eye Ray. The tarrakolichithidholder uses one random eye ray.

Lightning Storm (Costs 2 Actions). The tarrakolichithidholder uses Lightning Storm.

Ink Cloud (Costs 3 Actions). While underwater, the tarrakolichithidholder expels an ink cloud in a 60-foot radius. The cloud spreads around corners, and that area is heavily obscured to creatures other than the tarrakolichithidholder. Each creature other than the tarrakolichithidholder that ends its turn there must succeed on a DC 23 Constitution saving throw, taking 16 (3d10) poison damage on a failed save, or half as much damage on a successful one. A strong current disperses the cloud, which otherwise disappears at the end of the tarrakolichithidholder's next turn.