Actions

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: +17 to hit, reach 15 ft., one target. Hit: 15 (1d12 + 9) bludgeoning damage.   Bite. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 14 (1d10 + 9) piercing damage.

Bonus Actions

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.   Iron Spike. Yeenoghu causes an iron spike - 5 feet tall and 1 inch in diameter - to burst from the ground at a point he can see within 100 feet of him. Any creature in the space where the spike emerges must make a DC 25 Dexterity saving throw. On a failed save, the creature takes 27 (6d8) piercing damage and is restrained by being impaled on the spike. A creature can use an action to remove itself (or a creature it can reach) from the spike, ending the restrained condition.   Pack Rush. Each gnoll or hyena that Yeenoghu can see can use its reaction to move up to half it's its speed without provoking attacks of opportunity.   Incite the Pack. Until the start of his next turn, all gnolls and hyenas who can see or hear him have advantage on their next attack roll, saving throw or ability check

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 its 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 25 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.  

Mythic Actions

If Yeenoghu's Demonic Awakening trait has activated in the last hour, he can use the options below as legendary actions.   Cast a Spell (Costs 2 Actions). Yeenoghu casts a spell with casting time of 1 action.   Frightful Presence. Each creature of Yeenoghu 's choice within 60 feet of him and aware of him must succeed on a DC: 18 Wisdom saving throw or become frightened for 1 minute. A frightened creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. These later saves have disadvantage if Yeenoghu is within line of sight of the creature. If a creature succeeds on any of these saves or the effect ends on it, the creature is immune to Yeenoghu's Frightful Presence for the next 24 hours.  

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 causes 4 iron spikes - 5 feet tall and 1 inch in diameter - to burst from the ground at any points within his lair. Any creature in the space where the spike emerges must make a DC 25 Dexterity saving throw. On a failed save, the creature takes 27 (6d8) piercing damage and is restrained by being impaled on the spike. A creature can use an action to remove itself (or a creature it can reach) from the spike, ending the restrained condition.
• Each gnoll or hyena that Yeenoghu in his lair can use its reaction to move up to its speed and make one attack.
• Until the next initiative count 20, all gnolls and hyenas within the lair are enraged, causing them to have advantage on melee weapon attack rolls and causing attack rolls to have advantage against them.

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 there are few structures or signs of civilization on his layer of the Abyss.