Armor Class 20 (natural armor)
Hit Points 333 (23d12 + 184)
Speed 50 ft.
Saving Throws DEX +10, CON +15, WIS +14
Skills Intimidation +9, Perception +14
Damage Resistances cold, fire, lightning
Damage Immunities poison, [object Object]
Condition Immunities charmed, exhaustion, frightened, poisoned
Senses truesight 120 ft., passive Perception 24
Languages all, telepathy 120 ft.
Challenge 24
Legendary Resistance (3/Day). If Yeenoghu fails a saving throw, he can choose to succeed instead.
Magic Resistance. Yeenoghu has advantage on saving throws against spells and other magical effects.
Magic Weapons. Yeenoghu's weapon attacks are magical.
Rampage. When Yeenoghu reduces a creature to 0 hit points with a melee attack on his turn, Yeenoghu can take a bonus action to move up to half his speed and make a bite attack.
Multiattack. Yeenoghu makes three flail attacks. If an attack hits, he can cause it to create an additional effect of his choice or at random (each effect can be used only once per Multiattack): 1. The attack deals an extra 13 (2d12) bludgeoning damage. 2. The target must succeed on a DC 17 Constitution saving throw or be paralyzed until the start of Yeenoghu's next turn. 3. The target must succeed on a DC 17 Wisdom saving throw or be affected by the confusion spell until the start of Yeenoghu's next turn.
Flail. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 15 (1d12 + 9) bludgeoning damage.
Bite. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 14 (1d10 + 9) piercing damage.
Charge. Yeenoghu moves up to his speed.
Swat Away. Yeenoghu makes a flail attack. If the attack hits, the target must succeed on a DC 24 Strength saving throw or be pushed 15 feet in a straight line away from Yeenoghu. If the saving throw fails by 5 or more, the target falls prone.
Savage (Costs 2 Actions). Yeenoghu makes a bite attack against each creature within 10 feet of him.
Mordenkainen's Tome of Foes, p. 155