Arcanaloth

Medium fiend (yugoloth), neutral evil

Armor Class 17 (natural armor)

Hit Points 104 (16d8+32)

Speed 30 ft., fly 30 ft.

Saving Throws Dex +5, Int +9, Wis +7, Cha +7

Skills Arcana +13, Deception +9, Insight +9, Perception +7

Damage Resistances cold, fire, lightning, bludgeoning, piercing, and slashing from nonmagical weapons

Damage Immunities acid, poison

Condition Immunities charmed, poisoned

Senses truesight 120 ft.

Languages all, telepathy 120 ft.

Challenge 12 (8,400 XP)

Innate Spellcasting. The arcanaloth’s innate spellcasting ability is Charisma (spell save DC 15). The arcanaloth can innately cast the following spells, requiring no material components:

At will: alter self, darkness, heat metal, invisibility (self only), magic missile

Magic Resistance. The arcanaloth has advantage on saving throws against spells and other magical effects.

Magic Weapons. The arcanaloth’s weapon attacks are magical.

Spellcasting. The arcanaloth is a 16th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 17, +9 to hit with spell attacks). The arcanaloth has the following wizard spells prepared:

• Cantrips (at will): fire bolt, mage hand, minor illusion, prestidigitation

• 1st level (4 slots): detect magic, identify, shield, Tenser’s floating disk

• 2nd level (3 slots): detect thoughts, mirror image, phantasmal force, suggestion

• 3rd level (3 slots): counterspell, fear, fireball

• 4th level (3 slots): banishment, dimension door

• 5th level (2 slots): contact other plane, hold monster

• 6th level (1 slot): chain lightning

• 7th level (1 slot): finger of death

• 8th level (1 slot): mind blank

Actions

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) slashing damage. The target must make a DC 14 Constitution saving throw, taking 10 (3d6) poison damage on a failed save, or half as much damage on a successful one.

Teleport. The arcanaloth magically teleports, along with any equipment it is wearing or carrying, up to 60 feet to an unoccupied space it can see.

Variant: Summon Yugoloth (1/Day). The yugoloth attempts a magical summoning.

An arcanaloth has a 40 percent chance of summoning one arcanaloth.

A summoned yugoloth appears in an unoccupied space within 60 feet of its summoner, does as it pleases, and can’t summon other yugoloths. The summoned yugoloth remains for 1 minute, until it or its summoner dies, or until its summoner takes a bonus action to dismiss it.