Behir Lich

Gargantuan monstrosity, neutral evil

Armor Class

20 (natural armor)

Hit Points

310 (20d20+100)

Speed

80 ft., climb 60 ft.

Saves

Dex +11, Con +11, Int +6, Cha +8

Skills

Perception +9, Stealth +11

Damage Resistances

necrotic

Damage Immunities

lightning, poison

Condition Immunities

charmed, exhaustion, frightened, paralyzed, poisoned

Senses

darkvision 120 ft.

Languages

Common, Draconic

Challenge

21

Legendary Resistance (3/Day).

If the behir fails a saving throw, it can choose to succeed instead.

Serpent's Flurry.

Once on each of its turns when it misses with a claw attack, the behir can make another claw attack as part of the same action.

Magic Resistance

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

Innate Spellcasting

The behir's innate spellcasting ability is Charisma (spell save DC 16). The behir can innately cast the following spells, requiring no components. 2/day each: bestow curse, danse macabre 1/day each: chain lightning, power word stun

Actions

Lightning Breath (Recharge 5-6)

The behir exhales a line of lightning that is 60 ft. long and 5 ft. wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one.

Multiattack

The behir makes three attacks: one with its bite and two with its claws. It can replace both of its claw attacks with one constrict attack.

Bite

Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 24 (3d10+8) piercing damage.

Claw

Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 19 (3d6+8) piercing damage.

Constrict

Melee Weapon Attack: +14 to hit, reach 5 ft., one Large or smaller creature. Hit: 19 (2d10+8) bludgeoning damage plus 19 (2d10+8) slashing damage. The target is grappled (escape DC 16) if the behir isn't already constricting a creature, and the target is restrained until this grapple ends. Grappled: • A grappled creature's speed becomes 0, and it can't benefit from any bonus to its speed. • The condition ends if the grappler is incapacitated. • The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect, such as when a creature is hurled away by the thunderwave spell. Restrained: • A restrained creature's speed becomes 0, and it can't benefit from any bonus to its speed. • Attack rolls against the creature have advantage, and the creature's attack rolls have disadvantage. • The creature has disadvantage on Dexterity saving throws.

Legendary actions

Legendary Actions (3/Turn)

The behir can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature's turn. The behir regains spent legendary actions at the start of its turn.

Bite

The behir makes a bite attack.

Move

The behir moves up to its speed.

Crush (Costs 2 Actions)

The behir squeezes the creature it is grappling. The creature takes 15 (2d6 + 8) bludgeoning damage and must succeed on a DC 22 Constitution saving throw or become unable to breathe until the grapple ends.