Demonic Restoration. If Zuggtmoy dies outside the Abyss, her body dissolves into ichor, and she gains a new body instantly, reviving with all her Hit Points somewhere in Shedaklah.

Legendary Resistance (4/Day, or 5/Day in Lair). If Zuggtmoy fails a saving throw, she can choose to succeed instead.

Magic Resistance. Zuggtmoy has Advantage on saving throws against spells and other magical effects.

Multiattack. Zuggtmoy makes three Pseudopod attacks.

Pseudopod. Melee Attack Roll: +13 to hit, reach 10 ft. Hit: 24 (4d8 + 6) Force damage plus 18 (4d8) Poison damage. If the target is a creature, it has the Poisoned condition until the end of its next turn. While Poisoned, the target can't regain Hit Points.

Spellcasting. Zuggtmoy casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 23):

At Will: Detect Magic, Dispel Magic, Entangle, Locate Animals or Plants, Plant Growth

1/Day Each: Etherealness, Teleport

Infestation Spores (3/Day). Zuggtmoy releases spores that burst out in a cloud that fills a 20-foot-radius Sphere centered on her, and it lingers for 1 minute. Constitution Saving Throw: DC 23, any creature that starts its turn in this area or enters it for the first time on a turn. Failure: The target is infected with a disease called the spores of Zuggtmoy for 24 hours. While infected in this way, the target's body is slowly taken over by fungal growth, and at the end of that time, the target dies and reanimates as a Myconid Spore Servant under Zuggtmoy's control.

Mind Control Spores (Recharge 5–6). Zuggtmoy releases spores that burst out in a cloud that fills a 20-foot-radius Sphere centered on her, and it lingers for 1 minute. Wisdom Saving Throw: DC 23, any creature that starts its turn in this area or enters it for the first time on a turn. Failure: The target is infected with a disease called the influence of Zuggtmoy for 24 hours. While infected in this way, the target has the Charmed condition.

Protective Thrall. Trigger: Zuggtmoy is hit by an attack roll. Response: Zuggtmoy targets one Charmed creature within 10 feet, causing the target to be hit by the attack instead.

Legendary Action Uses: 3 (4 in lair). Immediately after another creature's turn, Zuggtmoy can expend a use to take one of the following actions. Zuggtmoy regains all expended uses at the start of each of his turns.

Decaying Strike. Zuggtmoy moves up to half her Speed, and she makes one Pseudopod attack.

Exert Will. Zuggtmoy targets up to four Charmed creatures she can see within 120 feet. Each target must take its Reaction to (A) move up to its Speed as Zuggtmoy directs without provoking Opportunity Attacks or (B) make one attack with Advantage and gain a +7 bonus to the damage roll against a target that Zuggtmoy designates. Zuggtmoy can't take this action again until the start of her next turn.

Summon Fungi. Zuggtmoy causes up to four (A) Gas Spore Fungi or (B) Violet Fungi to appear in unoccupied spaces that she can see within 120 feet. These creatures are under Zuggtmoy's control until they are destroyed or until she dismisses them as an Action. Zuggtmoy can't take this action again until the start of her next turn.