Infectious Blindness. When a creature that can see moves within 60 feet of the beholder for the first time in a turn or starts its turn there, it must succeed on DC 17 Charisma saving throw or become blinded until the end of its next turn.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 18 (5d6) piercing damage.

Void Rays. The beholder shoots three of the following void rays at random (reroll duplicates), choosing one non-aberration target thet can see within 120 feet of it:

1. Fusion Ray. The targeted creature must succeed on a DC 17 Dexterity saving throw or one of their wielded or worn metal objects becomes affected by the Heat Metal spell for 1 minute.
2. Deformation Ray. The targeted creature must succeed on a DC 17 Constitution saving throw or be polymorphed into a Nothic for 1 minute.
3. Insanity Ray. The targeted creature must succeed on a DC 17 Wisdom saving throw or be affected by a Crown of Madness spell 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. Phasing Ray. The targeted creature must succeed on a DC 17 Dexterity saving throw. On a failed save, the target is stunned until the end of its next turn. While stunned, the creature is invisible.
5. Scourging Ray. The targeted creature must make a DC 17 Constitution saving throw, taking 36 (8d8) force damage on a failed save, or half as much damage on a successful one. The beholder can push the creature up to 20 feet in a direction away of itself.
6. Neural Ray. If the target is a creature, it must succeed on a DC 17 Intelligence saving throw or be affected by a Phantasmal Killer for 1 minute.
7. Stasis Ray. The targeted creature must succeed on a DC 17 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target also gains 10 temporary hit points. The target awakens if it takes damage. 
8. Degradation Ray. The targeted creature must make a DC 17 Dexterity saving throw. On a failed save, the creature's ability scores are reduced by 2 until it completes a short or long rest.
9. Gauss Ray. If the target is a creature, it must succeed on a DC 17 Constitution saving throw or take 45 (10d8) radiant damage. If this damage reduces the creature to 0 hit points, its body is teleported to the Ethereal Plane.
10. Undeath Ray. The targeted creature must succeed on a DC 17 Dexterity saving throw or take 55 (10d10) necrotic damage. The target dies if the ray reduces it to 0 hit points and is then affected by an Animate Dead

The beholder can take 3 legendary actions, using the Void Ray option below. It 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 its turn.

Void Ray. The beholder uses one random void ray.