Adult Green Dragon

Huge dragon · CR 15

Armor Class 19

Hit Points 207 (18d12+90)

Speed fly 80 ft., swim 40 ft., 40 ft.

STR 23 +6

DEX 12 +1

CON 21 +5

INT 18 +4

WIS 15 +2

CHA 17 +3

Saving Throws CHA+8, CON+10, DEX+6, WIS+7

Skills deception +8, insight +7, perception +12, persuasion +8, stealth +6

Damage Immunities poison

Condition Immunities poisoned

Senses blindsight60 ft., darkvision120 ft. , passive Perception 22

Languages Common, Draconic

Traits

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/Ranged Weapon Attack: +11 to hit.: Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 7 (2d6) poison damage.
Claw. Melee/Ranged Weapon Attack: +11 to hit.: Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.
Tail. Melee/Ranged Weapon Attack: +11 to hit.: Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) 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 16 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). Melee/Ranged Weapon Attack: +0 to hit.: The dragon exhales poisonous gas in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 56 (16d6) poison damage on a failed save, or half as much damage on a successful one.

Legendary Actions

The Adult Green 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 creature 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) (Costs 2 Actions).: The dragon beats its wings. Each creature within 10 ft. of the dragon must succeed on a DC 19 Dexterity saving throw or take 13 (2d6 + 6) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.