Size
Huge
Type
fiend (devil)
Alignment
lawful evil
Armor Class
19 (natural armor)
Hit Points
300 (24d12 + 144)
Speed
30 ft., fly 50 ft.
Strength
29
Dexterity
17
Constitution
22
Intelligence
19
Wisdom
16
Charisma
23
Saving Throws
Dex +10, Con +13, Wis +10, Cha +13
Skills
Deception +13, Intimidation +13, Perception +10
Damage Resistances
bludgeoning, piercing, and slashing from nonmagical attacks that aren't silvered
Damage Immunities
cold, fire, poison
Condition Immunities
charmed, exhaustion, frightened, poisoned
Senses
truesight 120 ft.
Passive Perception
20
Languages
all, telepathy 120 ft.
Challenge Rating
22
Traits
Source
Description
Mordenkainen Presents: Monsters of the Multiverse p. 136, Mordenkainen's Tome of Foes p. 173
Proficiency Bonus
Description
+7
Legendary Resistance (3/Day)
Description
If Geryon fails a saving throw, he can choose to succeed instead.
Magic Resistance
Description
Geryon has advantage on saving throws against spells and other magical effects.
Regeneration
Description
Geryon regains 20 hit points at the start of his turn. If he takes radiant damage, this trait doesn't function at the start of his next turn. Geryon dies only if he starts his turn with 0 hit points and doesn't regenerate.
Actions
Multiattack
Description
Geryon makes one Claw attack and one Stinger attack.
Claw
Description
Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 23 (4d6 + 9) cold damage. If the target is Large or smaller, it is grappled (DC 24), and it is restrained until the grapple ends. Geryon can grapple one creature at a time. If the target is already grappled by Geryon, the target takes an extra 27 (6d8) cold damage.
Attack
Claw|16|4d6+9
Stinger
Description
Melee Weapon Attack: +16 to hit, reach 20 ft., one creature. Hit: 14 (2d4 + 9) force damage, and the target must succeed on a DC 21 Constitution saving throw or take 13 (2d12) poison damage and become poisoned until it finishes a short or long rest. The target's hit point maximum is reduced by an amount equal to half the poison damage taken. This reduction lasts until the poisoned condition is removed. The target dies if its hit point maximum is reduced to 0.
Attack
Stinger|16|2d4+9
Spellcasting
Description
Geryon casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 21):
At will: alter self (can become Medium when changing his appearance), detect magic, ice storm, invisibility (self only), locate object, suggestion, wall of ice
1/day: banishment
Teleport
Description
Geryon teleports, along with any equipment he is wearing and carrying, up to 120 feet to an unoccupied space he can see.
Lair Actions
Description
On initiative count 20 (losing initiative ties), Geryon can take one of the following lair actions; he can't take the same lair action two rounds in a row:
Banish. Geryon casts the banishment spell.
Chill Blast. Geryon causes a blast of cold to burst from the ground at a point he can see within 120 feet of him. The cold fills a cube, 10 feet on each side, centered on that point. Each creature in that area must succeed on a DC 21 Constitution saving throw or take 28 (8d6) cold damage.
Hateful Restraints. Geryon targets one creature he can see within 60 feet of him. The target must succeed on a DC 21 Wisdom saving throw or become restrained for 1 minute. The target can end the effect on itself if it deals any damage to one or more of its allies.
Legendary Actions
Legendary Actions (3/Turn)
Description
Geryon 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. Geryon regains spent legendary actions at the start of its turn.
Infernal Glare
Description
Geryon targets one creature he can see within 60 feet of him. The target must succeed on a DC 23 Wisdom saving throw or become frightened of Geryon until the end of its next turn.
Teleport
Description
Geryon uses Teleport.
Swift Sting (Costs 2 Actions)
Description
Geryon makes one Stinger attack.
Spells
alter self, detect magic, ice storm, invisibility, locate object, suggestion, wall of ice, banishment