Medium undead, neutral evil
- Armor Class
- 19 (natural armor)
- Hit Points
- 199 (21d8 + 105)
- Speed
- fly 40 ft., 30 ft.
- Challenge
- 22 (41,000 XP)
- Saving Throws
- Con +12, Int +15, Wis +12
- Skills
- Arcana +15, History +15, Insight +12, Perception +12
- Damage Resistances
- cold; lightning
- Damage Immunities
- necrotic; poison; bludgeoning, piercing, slashing from nonmagical attacks
- Condition Immunities
- blinded; charmed; deafened; exhaustion; frightened; paralyzed; petrified; poisoned; stunned
- Senses
- truesight 120 ft., passive Perception 22
- Languages
- Common, Draconic, Elvish
Traits
If Illmarrow fails a saving throw, she can choose to succeed instead.
Illmarrow has advantage on saving throws against spells and other magical effects.
Illmarrow's body turns to dust when she drops to 0 hit points, and her equipment is left behind. She gains a new body after 1d10 days, regaining all her hit points and becoming active again. The new body appears within two hundred miles of the location at which she was destroyed.
Actions
Ranged Spell Attack: +15 to hit, range 120 ft., one creature. Hit: 18 (4d8) necrotic damage, and the target can't regain hit points until the start of Illmarrow's next turn. If the target is undead, it also has disadvantage on attack rolls against Illmarrow until the end of her next turn.
Melee Weapon Attack: +10 to hit, reach 5 ft., one creature. Hit: 13 (3d6 + 3) slashing damage plus 10 (3d6) cold damage, and the target must succeed on a DC 20 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Illmarrow exhales poisonous gas in a 30-foot cone. Each creature in that area must make a DC 20 Constitution saving throw. On a failed save, a creature takes 35 (10d6) poison damage and is poisoned for 1 minute. While poisoned in this way, the creature can't regain hit points. On a successful save, the creature takes half as much damage and isn't poisoned.
A humanoid reduced to 0 hit points by this damage dies and rises at the start of Illmarrow's next turn as a zombie. The zombie acts immediately after Illmarrow in the initiative count and is permanently under her command, following her verbal orders.
Legendary Actions
Illmarrow casts a cantrip.
Illmarrow uses her Paralyzing Claw.
Illmarrow targets up to three creatures she can see within 30 feet of her. Each target must succeed on a DC 20 Wisdom saving throw or be frightened for 1 minute. A frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to Illmarrow's Frightening Presence for the next 24 hours.
Illmarrow recharges her Poison Breath and uses it.
Spellcasting
Illmarrow is a 20th-level spellcaster. Her spellcasting ability is Intelligence (spell save DC 23, +15 to hit with spell attacks). Illmarrow has the following wizard spells prepared: