Amphibious. The dragon can breathe air and water.
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.
Description
The most cunning and treacherous of true dragons, green dragons use misdirection and trickery to get the upper hand against their enemies. A green dragon is recognized by the crest that begins near its eyes and continues down its spine, reaching full height just behind the skull.
It doesn't. What makes you say that?
Green dragons are recognized by their... crest? Not because they're green... and a dragon?
https://www.reddit.com/r/dndnext/comments/2e682e/what_makes_the_green_dragon_work_in_lost_mines_of/