Sources
CR
Type
Size
Alignment
Movement

Arcanaloth

Medium Fiend (yugoloth), Neutral Evil

Armor Class 17 (natural armor)
Hit Points 104 (16d8 + 32)
Speed 30 ft., fly 30 ft.
STR
17
+3
DEX
12
+1
CON
14
+2
INT
20
+5
WIS
16
+3
CHA
17
+3
Saving Throws DEX +5, INT +9, WIS +7, CHA +7
Skills Arcana +13, Deception +11, Insight +11, Perception +7
Damage Resistances cold, fire, lightning; bludgeoning, piercing, slashing, from nonmagical attacks
Damage Immunities acid, poison
Condition Immunities Charmed, Poisoned
Senses truesight 120 ft., passive Perception 17
Languages all, telepathy 120 ft.
Challenge 12 (8,400 XP)

Traits

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

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

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.

Lore

Yugoloths are fickle fiends that inhabit the planes of Acheron, Gehenna, Hades, and Carceri. They act as mercenaries and are notorious for their shifting loyalties. They are the embodiments of avarice. Before serving under anyone's banner, a yugoloth asks the only question on its mind: What's in it for me?