Ancient Green Dragon

Amphibious. The dragon can breathe air and water.

Legendary Resistance (3/Day). When the dragon fails a saving throw, it can choose to succeed instead. When it does, it sheds some of its scales, which turn into dry leaves and blow away. If it has no more uses of this ability, its Armor Class is reduced to 19 until it finishes a long rest.

Woodland Stalker. When in a forested area, the dragon has advantage on Stealth checks. Additionally, when it speaks in such a place, it can project its voice such that it seems to come from all around, allowing it to remain hidden while speaking.

Blood Toxicity (While Bloodied). The first time each turn a creature hits the dragon with a melee attack while within 10 feet of it, that creature makes a DC 22 Dexterity saving throw, taking 10 (3d6) poison damage on a failure.

Innate Spellcasting. The dragons spellcasting ability is Charisma (save DC 19). It can innately cast the following spells, requiring no material components. 3/day each:animal messenger, tongues, modify memory, scrying, 1/day:mass suggestion, telepathic bond

Multiattack. The dragon attacks once with its bite and twice with its claws. In place of its bite attack it can Spit Poison.

Bite. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 30 (4d10 + 8) piercing damage plus 9 (2d8) poison damage.

Claw. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) slashing damage.

Tail. Melee Weapon Attack: +15 to hit, reach 20 ft., one target. Hit: 21 (3d8 + 8) bludgeoning damage and the dragon pushes the target 10 feet away.

Spit Poison. The dragon targets a creature within 60 feet forcing it to make a DC 22 Dexterity saving throw. The creature takes 22 (4d10) poison damage on a failure or half damage on a success. A creature that fails the save is also poisoned for 1 minute. The creature repeats the saving throw at the end of each of its turns taking 11 (2d10) poison damage on a failure and ending the effect on a success.

Poison Breath (Recharge 5-6). The dragon exhales poisonous gas in a 90-foot cone. Each creature in that area makes a DC 22 Constitution saving throw taking 80 (23d6) poison damage on a failed save or half damage on a success. A creature with immunity to poison damage that fails the save takes no damage but its poison immunity is reduced to resistance for the next hour.

Honeyed Words. The dragons words sow doubt in the minds of those who hear them. One creature within 60 feet who can hear and understand the dragon makes a DC 19 Wisdom saving throw. On a failure the creature must use its reaction if available to make one attack against a creature of the dragons choice with whatever weapon it has to do so moving up to its speed as part of the reaction if necessary. It need not use any special class features (such as Sneak Attack or Divine Smite) when making this attack. If it can't get in a position to attack the creature it moves as far as it can toward the target before regaining its senses. A creature immune to being charmed is immune to this ability.

Tail Attack. When a creature the dragon can see within 10 feet hits the dragon with a melee attack, the dragon makes a tail attack against it.

The dragon can take 3 legendary actions. Only one legendary action can be used at a time and only at the end of another creatures turn. It regains spent legendary actions at the start of its turn.

Honeyed Words. The dragon uses Honeyed Words.

Roar. Each creature of the dragons choice within 120 feet that can hear it makes a DC 19 Charisma saving throw. On a failure, it is frightened for 1 minute. A creature repeats the saving throw at the end of its turns, ending the effect on itself on a success. When it succeeds on a saving throw or the effect ends for it, it is immune to Roar for 24 hours.

Wing Attack. The dragon beats its wings. Each creature within 15 feet makes a DC 22 Dexterity saving throw. On a failure, it is pushed 10 feet away and knocked prone. The dragon can then fly up to half its fly speed.