Beholder Boss (Eye Tyrant)

Legendary Resistance (3/Day). If the Beholder fails a saving throw, he can choose to succeed instead.

Antimagic Cone. The Beholder'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 Beholder decides which way the cone faces and whether the cone is active. The area works against the Beholder's own eye rays.

Eye Tentacles. Ten eyes float around the Beholder and create their Eye ray effects. Each eye is an object that has AC 24 and 20 hit points, and is protected by a psionic shield that makes it immune to damage. After an eye creates a Eye ray effect, it loses its psionic shield until the start of the Beholder's next turn. If an eye is destroyed, the Beholder loses one Eye ray of the Dm's choice. And a new eye pops out of the Beholder's face to replace it at the end of their next turn (This replacement does not have any Eye rays that it had before it was cut off.).

Mimicry. The Beholder can mimic simple sounds of speech it has heard, in any language. A creature that hears the sounds can tell they are imitations with a successful DC 17 Wisdom (Insight) check.

Multiattack. The Beholder makes three Bite attacks.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 14 (4d6) piercing damage. 

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

1. Charm Ray. The targeted creature must succeed on a DC 17 Wisdom saving throw or be charmed by the beholder for 1 hour, or until the beholder harms the creature or one of their allies.

2. Paralyzing Ray. The targeted creature must succeed on a DC 17 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 17 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 17 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 17 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 17 Strength saving throw or the Beholder moves it up to 30 feet in any direction and take 7 (2d6) force damage at the end of the move. It is restrained by the ray’s telekinetic grip until the start of the beholder’s next turn or until the beholder 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 beholder 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 17 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 17 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 restoration spell or other magic.

9. Disintegration Ray. If the target is a creature, it must succeed on a DC 17 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.

11. Fire Beam. The targeted creature must make a DC 17 Dexterity saving throw. On a failed save, the target takes 36 (8d8) fire damage and catches fire, taking 9 (2d8) fire damage at the start of each of their turns for 1 minute (save ends at end of turn.). Any creature can use their action to douse the fire, ending the effect early.

12. Freeze Ray. The targeted creature must succeed on a DC 17 Dexterity saving throw or take 35 (10d6) cold damage.

13. Compulsion Beam. The targeted creature must succeed on a DC 17 intelligence saving throw or use their reaction, if available, to move up to their speed toward the closet ally they can see and make one weapon attack against them. Creatures that can't be charmed are unaffected. 

14. Memory Beam. The targeted creature must make a DC 17 intelligence saving throw. On a failed save, if the creature has unexpended spell slots, they expend a spell slot of their highest remaining level, with no effect. If they don't have unexpended spell slots, they instead lose proficiency with a weapon they're holding or carrying for 1 minute (save ends at end of turn.).

15. Toxic Vapor's. The Beholder chooses a point he can see within 120 feet of him. Each creature of his choice within 10 feet of the point must succeed on a DC 17 Constitution saving throw or become poisoned for 1 minute (save ends at end of a turn.).

16. Telekinetic Field. The Beholder chooses a point he can see within 120 feet of them. Each creature of his choice within 10 feet of the point must succeed on a DC 17 Strength saving throw or be moved up to 30 feet in any direction and take 7 (2d6) force damage at the end of the move.

Additionally, Beholder can target any object within 10 feet of the point that weighs 300 pounds or less and isn't being worn or carried, moving it up to 30 feet in any direction. Beholder can also exert fine control on objects with this effect, such  as manipulating a simple tool or opening a door or a container.

17. Chain Lightning Bolt. The Beholder shoots a 5-foot-wide, 120 foot long line of lightning. Each creature in the line must succeed on a DC 17 Dexterity saving throw, the primary target taking 36 (8d8) lightning damage and the secondary targets with 30 feet of the primary target take 11 (3d8) lightning damage each on a failed save, or half as much damage on a successful one.

18. Moon Beam. The Beholder shoots silvery beam of pale light shines down in a 5-foot-radius, 40-foot-high cylinder centered on a point within range. Until the spell ends, dim light fills the cylinder.

When a creature enters the spell’s area for the first time on a turn or starts its turn there, it is engulfed in ghostly flames that cause searing pain, and it must make a DC 17 Constitution saving throw. It takes 16 (3d10) radiant damage on a failed save, or half as much damage on a successful one. A shape changer makes its saving throw with disadvantage. If it fails, it also instantly reverts to its original form and can’t assume a different form until it leaves the spell’s light. On each of Beholders turns after it uses this ray, it can use its action to move the beam up to 60 feet in any direction.

19. Explosion. The Beholder chooses  a point he can see within 120 feet of him. Each creature within 10 feet of the point must make a DC 17 Dexterity saving throw, taking 45 (10d8) fire damage on a failed save, or half has much damage on a successful one.

20. Greater Death Ray. The targeted creature must succeed on a DC 17 Constitution saving throw or immediately take 55 (10d10) necrotic damage and lose 9 (2d8) hit points at the start  of each of their turns. If this effect reduces a target's hit points to 0, they die. The effect ends if the Beholder dies or can't see the target. This ray effect can't be used while this effect persists.

Create Food and Water. The Beholder magically creates enough food and water to sustain itself for 24 hours.

Aggressive. As a bonus action, the Beholder can move up to its speed toward a hostile creature that it can see.

Spell Reflection. If the Beholder makes a successful saving throw against a spell, or a spell attack misses it, the Beholder can choose another creature (including the spellcaster) it can see within 120 feet of it. The spell targets the chosen creature instead of the Beholder. 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.

Away with You! When a creature within 5 feet of the Beholder hits them with a melee attack, the Beholder can use Telekinetic Ray on the attacker.

Cower! When a creature hits the Beholder with an attack, he shoots a Fear Ray at them. The creature must succeed on a DC 17 Wisdom saving throw or take 21 (6d6) psychic damage and become frightened of the Beholder for 1 minute (save ends at end of turn).

The Beholder can take 3 legendary actions. He can take only one legendary action at a time and only at the end of another creature’s turn. The Beholder regains spent legendary actions at the start of his turn.

Bite Attack. The Beholder does one extra bite attack.

Eye Ray. The Beholder uses one random eye ray.

The Beholder has three villain actions. He can take each action once during an encounter after an enemy creature's turn. He can take these actions in any order but can only use one per round.

Action 1: Disruption Beams. The Beholder shoots a psionic disruption beam at three creatures he can see with 120 feet of him. Each target must make a DC 17 Wisdom saving throw. On a failed save, whenever the target makes more than one weapon attack on a turn or casts a spell that isn't a cantrip, they take 14 (4d6) psychic damage. This effect lasts for 1 minute (save ends at end of turn).

Action 2: Disappearing Act. The Beholder turns invisible until the end of his next turn and teleports up to 120 feet to an unoccupied space he can see.

Action 3: Megabeam. The Beholder unleashes the effects of all of his remaining eye rays at once in a 20-foot-wide, 120-foot-long line. Each creature in the area must make a save against two random eye effects from the Beholders Eye Rays (reroll duplicates for each target). If the effect usually affects an area, it instead only affects individual creatures.