Green Dragon Wyrmling

5e compatible shield

Medium dragon, lawful evil

Armor Class 17 (natural armor)
Hit Points 38 (7d8 + 7)
Speed 30 ft., fly 60 ft., swim 30 ft.

STR DEX CON INT WIS CHA
15 (+2) 12 (+1) 13 (+1) 14 (+2) 11 (+0) 13 (+1)

Saving Throws Dex +3, Con +3, Wis +2, Cha +3
Skills Perception +4, Stealth +3
Damage Resistances 
Damage Immunities poison
Condition Immunities poisoned
Senses blindsight 10 ft., darkvision 60 ft., passive Perception 14
Languages Draconic
Challenge 2 (450 XP)

Amphibious. The dragon can breathe air and water.

Actions

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 7 (1d10 + 2) piercing damage plus 3 (1d6) poison damage.

Poison Breath (Recharge 5–6). The dragon exhales poisonous gas in a 15-foot cone. Each creature in that area must make a DC 11 Constitution saving throw, taking 21 (6d6) poison damage on a failed save, or half as much damage on a successful one.