Beholdragon

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

Breath Weapons. The beholdragon shoots three of the following breath weapons at random (reroll duplicates), choosing one to three targets it can see within 120 feet of it:

1. Acid Breath. The beholdragon exhales acid in a 60-­foot line that is 5 feet wide. Each creature in that line must make a DC 18 Dexterity saving throw, taking 54 (12d8) acid damage on a failed save, or half as much damage on a successful one.
2. Lightning Breath. The beholdragon exhales lightning in a 90-­foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.
3. Poison Breath. The beholdragon exhales poisonous gas in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 56 (16d6) poison damage on a failed save, or half as much damage on a successful one.
4. Fire Breath. The beholdragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much damage on a successful one.
5. Debilitating Breath. The beholdragon exhales a pulse of high-pitched, nearly inaudible sound in a 60-foot cone. Each creature in that cone must make a DC 18 Constitution saving throw. On a failed save, the creature takes 45 (13d6) thunder damage and is incapacitated until the end of its next turn. On a successful save, the creature takes half as much damage and isn’t incapacitated.
6. Cold Breath. The beholdragon exhales an icy blast in a 60-foot cone. Each creature in that area must make a DC 19 Constitution saving throw, taking 54 (12d8) cold damage on a failed save, or half as much damage on a successful one.
7. Ash Breath. The beholdragon exhales ash in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) acid damage and being blinded on a failed save, or half as much damage on a successful one.
8. Sandstorm Breath. The beholdragon exhales sand in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) piercing damage on a failed save, or half as much damage on a successful one.
9. Rainbow Breath. The beholdragon exhales a rainbow beam in a 90-­foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) radiant damage on a failed save, or half as much damage on a successful one.
10. Slime Breath. The beholdragon exhales 1d6 Ochre Jellies with an added flying speed of 50 ft.

The beholdragon can take 3 legendary actions, using the Breath Weapon option below. It can take only one legendary action at a time and only at the end of another creature’s turn. The beholdragon regains spent legendary actions at the start of its turn.

Breath Weapon. The beholder uses one random breath weapon.