Armor Class 17 (natural armor)
Hit Points 405 (30d12 + 210)
Speed 40 ft., fly 40 ft.
Saving Throws DEX +10, CON +15, WIS +13
Skills Arcana +13, Perception +13
Damage Resistances cold, fire, lightning
Damage Immunities necrotic, poison, [object Object]
Condition Immunities charmed, exhaustion, frightened, poisoned
Senses truesight 120 ft., passive Perception 22
Languages all, telepathy 120 ft.
Challenge 26
Legendary Resistance (3/Day). If Orcus fails a saving throw, he can choose to succeed instead.
Magic Resistance. Orcus has advantage on saving throws against spells and other magical effects.
Master of Undeath. Orcus can cast animate dead (at will) and create undead (3/day). He chooses the level at which the spells are cast, and the creatures created by them remain under his control indefinitely. Additionally, he can cast create undead even when it isn't night.
Special Equipment. Orcus wields the Wand of Orcus.
Multiattack. Orcus makes three Wand of Orcus, Tail, or Necrotic Bolt attacks.
Wand of Orcus. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 24 (3d8 + 11) bludgeoning damage plus 13 (2d12) necrotic damage.
Tail. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) force damage plus 9 (2d8) poison damage.
Necrotic Bolt. Ranged Spell Attack: +15 to hit, range 120 ft., one target. Hit: 29 (5d8 + 7) necrotic damage.
Conjure Undead (1/Day). While holding the Wand of Orcus, Orcus conjures type=undead whose combined average hit points don't exceed 500. These creatures magically rise up from the ground or otherwise form in unoccupied spaces within 300 feet of Orcus and obey his commands until they are destroyed or until he dismisses them as an action.
Attack. Orcus makes one Tail or Necrotic Bolt attack.
Creeping Death (Costs 2 Actions). Orcus chooses a point on the ground that he can see within 100 feet of him. A cylinder of swirling necrotic energy 60 feet tall and with a 10-foot radius rises from that point and lasts until the end of Orcus's next turn. Creatures in that area have vulnerability to necrotic damage.
Mordenkainen Presents: Monsters of the Multiverse, p. 204