Geryon

Traits

Legendary Resistance (3/Day)

If Geryon fails a saving throw, he can choose to succeed instead.

Magic Resistance

Geryon has advantage on saving throws against spells and other magical effects.

Magic Weapons

Geryon's weapon attacks are magical.

Regeneration

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

Geryon makes two attacks: one with his claws and one with his stinger.

Claws

Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 23 (4d6 + 9) slashing damage. If the target is Large or smaller, it is grappled (DC 24) and 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) slashing damage.

Stinger

Melee Weapon Attack: +16 to hit, reach 20 ft., one creature. Hit: 14 (2d4 + 9) piercing 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 it takes. If its hit point maximum drops to 0, it dies. This reduction lasts until the poisoned condition is removed.

Teleport

Geryon magically teleports, along with any equipment he is wearing and carrying, up to 120 feet to an unoccupied space he can see.

Legendary action uses: 3. The creature can use one option at the end of another creature’s turn and regains spent uses at the start of its turn.

Legendary actions

Infernal Glare

Geryon targets one creature he can see within 60 feet of him. If the target can see Geryon, the target must succeed on a DC 23 Wisdom saving throw or become frightened of Geryon until the end of its next turn.

Swift Sting (Costs 2 Actions)

Geryon attacks with his stinger.

Teleport

Geryon uses his Teleport action.

Innate Spellcasting

Geryon's innate spellcasting ability is Charisma (spell save DC 21). He can innately cast the following spells, requiring no material components:

At will: alter self (can become Medium when changing his appearance), detect magic, geas, ice storm, invisibility (self only), locate object, suggestion, wall of ice

1/day each: divine word, symbol (pain only)

Lair actions

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

• 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.
• 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.
• Geryon casts the banishment spell.

Regional effects

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

• Intelligent creatures within 1 mile of the lair frequently see shimmering portals leading to places they consider safe. Passing through a portal always deposits a traveler somewhere in Stygia.
• Freezing strong winds howl around the area within 1 mile of the lair.
• Howls and screams fill the air within 1 mile of the lair. Any creature that finishes a short or long rest in this area must succeed on a DC 21 Wisdom saving throw or derive no benefit from the rest.

If Geryon dies, these effects fade over the course of 1d10 days.