Monster
Ancient Green Dragon
Official reference · XMM · 2024
- Creature type
- Dragon
- Size
- Gargantuan
- Armor class
- 21
- Hit points
- 402 (23d20 + 161)
- Speed
- Walk 40 ft., Fly 80 ft., Swim 40 ft.
- Challenge rating
- 22
- Alignment
- Lawful Evil
- Strength
- 27
- Dexterity
- 12
- Constitution
- 25
- Intelligence
- 20
- Wisdom
- 17
- Charisma
- 22
- Passive Perception
- 27
- Initiative
- +15
- Saving Throws
- dex: +8; wis: +10
- Skills
- deception: +13; perception: +17; persuasion: +13; stealth: +8
- Senses
- Blindsight 60 ft., Darkvision 120 ft.
- Languages
- Common, Draconic
- Immunities
- poison
- Condition Immunities
- poisoned
Traits
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.
Actions
Multiattack
The dragon makes three Rend attacks. It can replace one attack with a use of Spellcasting to cast Mind Spike (level 5 version).
Rend
Melee Attack: +15, reach 15 ft. Hit: 17 (2d8 + 8) Slashing damage plus 10 (3d6) Poison damage.
Poison Breath (Recharge 5–6)
Constitution Saving Throw: DC 22, each creature in a 90-foot Cone. Failure: 77 (22d6) Poison damage. Success: Half damage.
Legendary action uses: 3 (4 in its lair). The creature can use one option at the end of another creature’s turn and regains spent uses at the start of its turn.
Legendary actions
Mind Invasion
The dragon uses Spellcasting to cast Mind Spike (level 5 version).
Noxious Miasma
Constitution Saving Throw: DC 21, each creature in a 30-foot-radius Sphere centered on a point the dragon can see within 90 feet. Failure: 17 (5d6) Poison damage, and the target takes a -2 penalty to AC until the end of its next turn. Success or Failure: 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.
The dragon casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 21):
At will: Detect Magic, Mind Spike (level 5 version)
1/day each: Geas, Modify Memory
Regional effects
The region containing an adult or ancient green dragon's lair is warped by its presence, creating the following effects:
- Beast Spies: Tiny Beasts magically gain the ability to understand Draconic and can communicate telepathically with the dragon while within 1 mile of the lair.
- Poisonous Thicket: Ordinary plants growing within 1 mile of the lair poison the air around them. Whenever a creature other than the dragon or its allies finishes a Long Rest in that area, it must succeed on a DC 15 Constitution saving throw or have the Poisoned condition for 1 hour.
If the dragon dies or moves its lair elsewhere, these effects end immediately.