Arcanaloth

Core

Damage Resistances: cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities: acid, poison
Condition Immunities: charmed, poisoned

Traits: 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:

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:

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.