Dexterity +9, Constitution +14, Wisdom +9, Charisma +11
Perception +16, Stealth +9
Blindsight 60 ft, Darkvision 120 ft
Common, Draconic
Acid
Traits
Amphibious
The Ancient Black Dragon can breathe air and water.
Legendary Resistance
If the Ancient Black Dragon fails a saving throw, it can choose to succeed instead.
Legendary Actions
Actions
Multiattack
The Ancient Black Dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.
Bite
+15 to hit, range 15 ft. Hit: 19 (2d10 + 8) piercing damage.
Claw
+15 to hit, range 10 ft. Hit: 15 (2d6 + 8) slashing damage.
Tail
+15 to hit, range 20 ft. Hit: 17 (2d8 + 8) bludgeoning damage.
Acid Breath
The Ancient Black Dragon exhales acid in a . Each creature in that line must make a saving throw, taking damage on a failed save, or half as much damage on a successful one.
Frightful Presence
Each creature of the Ancient Black Dragon's choice that is within of the dragon and aware of it must succeed on a saving throw or become frightened for . A creature can repeat the saving throw at the end of each of its turns, 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 Ancient Black Dragon's for the next 24 hours.
Legendary Actions
Detect
The Ancient Black Dragon makes a Wisdom (Perception) check.
Tail Attack
The Ancient Black Dragon makes a tail attack.
Wing Attack
The Ancient Black Dragon beats its wings. Each creature within of the Ancient Black Dragon must succeed on a saving throw or take damage and be knocked prone. The Ancient Black Dragon can then fly up to half its flying speed.