Armor Class 19 (natural armor)
Hit Points 255 (30d8 + 120)
Speed 30 ft.
Saving Throws INT +12, WIS +13, CHA +14
Skills Arcana +12, Deception +20, Insight +13, Intimidation +14, Performance +14, Persuasion +20
Damage Resistances cold, [object Object]
Damage Immunities fire, poison, psychic
Condition Immunities charmed, poisoned
Senses darkvision 120 ft., passive Perception 17
Languages Celestial, Common, Draconic, Infernal, telepathy 120 ft.
Challenge 20
Contractually Obligated. Zagum has advantage to hit creatures under an infernal contract and when he hits such creatures he delivers an additional 9 (2d8) damage of a type the target is most vulnerable to. A creature bound under an infernal contract also makes all saving throws against effects originating from Zagum with disadvantage.
Devil's Sight. Magical darkness doesn't impede Zagum's darkvision.
Magic Resistance. Zagum has advantage on saving throws against spells and other magical effects.
Multiattack. Zagum makes three attacks with Disarming Tongue or Oration.
Disarming Tongue. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 10 (3d4 + 3) slashing damage. A target hit by this attack has vulnerability to psychic damage until the start of their next turn.
Oration. Ranged Spell Attack: +14 to hit, range 60 ft., one target. Hit: 35 (6d8 + 8) psychic damage.
Legal Jargon (Recharge 4–6). Zagum chooses a point he can see within 90 feet of him. All creatures within a 20-foot-radius sphere centered on that point must make a DC 22 Wisdom saving throw. Creatures that fail the save are confused for up to 1 minute and must roll a d10 at the start of each of their turns. On a 1, a creature moves in a random direction then ends their turn. On a 2-6, a creature can't use actions this turn. On a 7-8, a creature must use their action to make a melee attack against a randomly determined creature within their reach that is not a Fiend. On a 9-10, a creature can move and act normally. A confused creature may repeat the saving throw at the end of its turn, ending the effect on a success.
CoA, p. 210