Ancient Black Dragon

Stat block

Cha

22

Con

25

Dex

14

Int

16

Str

27

Wis

15

Speed

Fly: 80; Swim: 40; Walk: 40

Senses

blindsight 60 ft., darkvision 120 ft., passive Perception 26

Skills

Stealth: 9; Perception: 16

Actions

• Multiattack. The dragon makes three Rend attacks. It can replace one attack with a use of Spellcasting to cast Acid Arrow (level 4 version).
• Rend. Melee Attack Roll: +15, reach 15 ft. 17 (2d8 + 8) Slashing damage plus 9 (2d8) Acid damage.
• Acid Breath. Dexterity Saving Throw: DC 22, each creature in a 90-foot-long, 10-foot-wide Line. Failure: 67 (15d8) Acid damage. Success: Half damage.
• Spellcasting. The dragon casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 21, +13 to hit with spell attacks): - **At Will:** Detect Magic, Fear, Acid Arrow - **1/Day Each:** Create Undead, Speak with Dead, Vitriolic Sphere

Hit dice

21d20 + 147

Languages

Common, Draconic

Armor detail

natural armor

Saving throws

Wisdom: 9; Dexterity: 9

Damage immunities

acid

Legendary actions

• Cloud of Insects. Dexterity Saving Throw: DC 21, one creature the dragon can see within 120 feet. Failure: 33 (6d10) Poison damage, and the target has Disadvantage on saving throws to maintain Concentration until the end of its next turn. Failure or Success: The dragon can't take this action again until the start of its next turn.
• Frightful Presence. The dragon uses Spellcasting to cast Fear. The dragon can't take this action again until the start of its next turn.
• Pounce. The dragon moves up to half its Speed, and it makes one Rend attack.

Special abilities

• Amphibious. The dragon can breathe air and water.
• Legendary Resistance (4/Day, or 5/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.