Combustible Poison. If the dragon breaths the fire in the same area as poison, the poison on the ground ignites, creating hazardous terrain in the area. Creatures moving in or starting in this area take 7 (2d6) fire damage per instance.

Boiling Venom. If the same creature is hit by a Bite attack from both heads, the creature must make a DC 16 Constitution saving throw, taking (4d6) and becomes poisoned, or half as much damage on a successful one.

Two Heads. The dragon has advantage on Wisdom (Perception) checks and on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

Amphibious. The dragon can breathe air and water.

Multiattack. The dragon makes four attacks: two with its bite and two with its claws.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 12 (2d6 + 5) piercing damage plus 3 (1d6) fire damage or plus 3 (1d6) poison damage depending on the head.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Fire Poison Breath (Recharge 5–6). The dragon exhales two 20-foot cones, one fire, one poison. Each creature in that area of the fire breath must make a DC 16 Dexterity saving throw, taking 28 (8d6) fire damage on a failed save, or half as much damage on a successful one. Each creature in that area of the poison breath must make a DC 15 Constitution saving throw, taking 28 (8d6) fire damage on a failed save, or half as much damage on a successful one.