Watcher

Antimagic Cone. The beholder's central eye creates an area of antimagic, as in the antimagic field spell, in a 60 ft. cone. At the start of each of it's turns, the beholder decides which way the cone faces and whether the cone is active. This area works against the beholder's own eye rays.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., 1 target. Hit: 9 (1d8 + 5) piercing damage. 

Eye Rays. The beholder shoots three of the magical eye rays at random (reroll duplicates), choosing one to three targets it can see within 100 feet of it.                            

1. Charm Ray. The targeted creature must succeed on DC 14 Wisdom saving throw or be charmed by the beholder for 1 hour, or until the beholder harms the creature.

2. Fear Ray. The targeted creature must succeed on a DC 14 Wisdom saving throw or become frightened for 1 minute. The creature can repeat the saving throw at the beginning at each of it's turns, ending the effect on itself on a success.

3. Slowing Ray. The target must make a DC 14 Dexterity saving throw. On a failed save, the target's speed is halved for 1 minute. In addition, the target can't take reactions, and it can either take an action or a bonus action, not both. The target can repeat the saving throw at the beginning of each of its turns, ending the effect on itself on a success.

4. Enervation Ray. The targeted creature must make a DC 14 Constitution saving throw. On a fail, it takes 27 (6d8) necrotic damage on a failed save, or half as much damage on a success.

5. Telekinetic Ray. If the target is a creature, it must succeed on a DC 14 Strength saving throw or the beholder moves it up to 30 feet in any direction. 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 200 pounds of 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.

6. Sleep Ray. The targeted creature must succeed on a DC 14 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 or undead.