Monster
Ancient Black Dragon
Gargantuan dragon, chaotic evil
- Armor Class
- 22 (natural armor)
- Hit Points
- 367 (21d20 + 147)
- Speed
- 40 ft., fly 80 ft., swim 40 ft.
- STR
- 27 (+8)
- DEX
- 14 (+2)
- CON
- 25 (+7)
- INT
- 16 (+3)
- WIS
- 15 (+2)
- CHA
- 19 (+4)
- Saving Throws
- Dex +9, Con +14, Wis +9, Cha +11
- Skills
- Perception +16, Stealth +9
- Damage Immunities
- acid
- Senses
- blindsight 60 ft., darkvision 120 ft., passive Perception 26
- Languages
- Common, Draconic
- Challenge
- 21 (33,000 XP)
- Proficiency Bonus
- +7
Amphibious. The dragon can breathe air and water.
Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.
Bite. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 9 (2d8) acid damage.
Claw. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.
Tail. Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.
Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 19 Wisdom saving throw or become frightened for 1 minute. 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 dragon's Frightful Presence for the next 24 hours.
Acid Breath (Recharge 5-6). The dragon exhales acid in a 90-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 67 (15d8) acid damage on a failed save, or half as much damage on a successful one.
Legendary Actions
The ancient black dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The ancient black dragon regains spent legendary actions at the start of its turn.
Detect. The dragon makes a Wisdom (Perception) check.
Tail Attack. The dragon makes a tail attack.
Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 15 ft. of the dragon must succeed on a DC 23 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.