Auntie Gas

Amphibious. The hag can breathe air and water.

Innate Spellcasting: Standard Green Hag Spell List (Vicious Mockery, Invisible Passage)

Mimicry. The hag can mimic animal sounds and humanoid voices. A creature that hears the sounds can tell they are imitations only with a successful DC 14 Wisdom (Insight) check.

Silent but Deadly: Auntie Gas' movement does not provoke an opportunity attack when obscured by fog or gas.

Multiattack. The hag makes two Claw attacks.

Claw. Melee Attack Roll: +6, reach 5 ft. Hit: 8 (1d8 + 4) Slashing damage plus 3 (1d6) Poison damage.

Gastric Thunder (Recharge 5): Auntie Gas turns and expels a blast of magically potent gas in a 15ft cone. Each creature in that area must make a DC 14 Constitution saving throw.

• Failure: 21 (6d6) poison damage and is Poisoned for 1 minute.
• Success: Half damage and not poisoned.
• Note: If a fire hits this cone, it explodes for an extra 1d6 fire damage.

Spellcasting. The hag casts one of the following spells, requiring no Material components and using Wisdom as the spellcasting ability (spell save DC 12, +4 to hit with spell attacks):

At Will: Dancing Lights, Disguise Self (24-hour duration), Invisibility (self only, and the hag leaves no tracks while Invisible), Minor Illusion, Ray of Sickness (level 3 version)

Propulsion Jump: When Auntie Gas takes damage, she can use her reaction to release a sudden burst of gas, flying up to 30ft away without provoking opportunity attacks.