Actions

Multiattack. Yeenoghu makes three flail attacks. If an attack hits, he can cause it to create and 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.

Legendary Actions

Yeenoghu can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. Yeenoghu regains spent legendary actions at the start of his turn.   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.

Lair Actions

On initiative count 20 (losing initiative ties), Yeenoghu can take a lair action to cause one of the following effects; he can't use the same effect two rounds in a row:  

Yeenoghu's lair in the Abyss is called the Death Dells, its barren hills and ravines serving as one great hunting ground, where he pursues captured mortals in a cruel game. Yeenoghu's lair is a place of blood and death, populated by gnolls, hyenas, and ghouls, and theere are few structures or signs of civilization on his layer of the Abyss.

Regional Effects

The region containing Yeenoghu's lair is warped by his magic, creating one or more of the following effects: