Ancient Green Dragon

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 10 (3d6) poison damage.

Claw. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 22 (4d6 + 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.

Poison Breath (Recharge 5–6). The dragon exhales poisonous gas in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 77 (22d6) poison damage on a failed save, or half as much damage on a successful one.

Legendary Actions

The 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 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 feet 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.

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 Roll: +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.

Spellcasting. 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

Legendary Actions

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, the dragon can expend a use to take one of the following actions. The dragon regains all expended uses at the start of each of its turns.

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. Failure or Success: 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.