Young Green Dragon

Large dragon, lawful evil

Armor Class 18 (natural armor)
Hit Points 136 (16d10 + 48)
Speed 40 ft., fly 80 ft., swim 40 ft.

Saving Throws Dex +4, Con +6, Wis +4, Cha +5
Skills Deception +5, Perception +7, Stealth +4
Damage Immunities poison
Condition Immunities poisoned
Senses blindsight 30 ft., darkvision 120 ft., passive Perception 17
Languages Common, Draconic
Challenge 8 (3,900 XP)

Amphibious. The dragon can breathe air and water.

Actions

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.
Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 4) piercing damage plus 7 (2d6) poison damage.
Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.
Poison Breath (Recharge 5–6). The dragon exhales poisonous gas in a 30‐foot cone. Each creature in that area must make a DC 14 Constitution saving throw, taking 42 (12d6) poison damage on a failed save, or half as much damage on a successful one.