Legendary Resistance (3/Day). If the molydeus fails a saving throw, it can choose to succeed instead.

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

Spellcasting. The molydeus casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 22):

At will: dispel magic, polymorph, telekinesis, teleport

3/day: lightning bolt

Multiattack. The molydeus makes one Demonic Weapon attack, one Snakebite attack, and one Wolf Bite attack.

Demonic Weapon. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit:35 (4d12 + 9) force damage. If the target has at least one head and the molydeus rolled a 20 on the attack roll, the target is decapitated and dies if it can't survive without that head. A target is immune to this effect if it takes none of the damage, has legendary actions, or is Huge or larger. Such a creature takes an extra 27 (6d8) force damage from the hit.

Snakebite. Melee Weapon Attack: +16 to hit, reach 15 ft., one creature. Hit:16 (2d6 + 9) poison damage. The target must succeed on a DC 22 Constitution saving throw, or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target transforms into a manes if this reduces its hit point maximum to 0. This transformation can be ended only by a wish spell.

Wolf Bite. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit:25 (3d10 + 9) necrotic damage.

Attack. The molydeus makes one Demonic Weapon or Snakebite attack.

Move. The molydeus moves without provoking opportunity attacks.

Cast a Spell (Costs 2 Actions). The molydeus uses Spellcasting.