Balor Bargith

Death Throes. When the balor dies, it explodes, and each creature within 30 feet of it must make a DC 20 Dexterity saving throw, taking  2 (2d100) fire damage on a failed save, or half as much damage on a successful one. The explosion ignites flammable objects in that area that aren't being worn or carried, and it destroys the balor's weapons.

Fire Aura. At the start of each of the balor's turns, each creature within 5 feet of it takes 30 (3d20) fire damage, and flammable objects in the aura that aren't being worn or carried ignite. A creature that touches the balor or hits it with a melee attack while within 5 feet of it takes 30 (3d20) fire damage.

Magic Resistance. The balor has advantage on saving throws against spells and other magical effects.

Magic Weapons. The balor's weapon attacks are magical.

Multiattack. The balor makes two attacks: one with its longsword and one with its whip.

GreatAxe. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit:  23 (3d10 + 8) slashing damage plus 25 (5d10) lightning damage. If the balor scores a critical hit, it rolls damage dice three times, instead of twice.

Whip. Melee Weapon Attack: +14 to hit, reach 30 ft., one target. Hit: 20 (4d6 + 8) slashing damage plus 10 (3d6) fire damage, and the target must succeed on a Strength contest  or be pulled up to 25 feet toward the balor.

Teleport. The balor magically teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.

Fire Breath (Recharge 5–6). The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one.

Frightful Presence. Each creature of the Balor's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 21 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the Balor Frightful Presence for the next 24 hours.

Legendary Resistance (3/Day). If the Balor fails a saving throw, it can choose to succeed instead.

Bite. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 36 (4d12 + 10) piercing damage. If the target is a creature, it is grappled (escape DC 25). Until this grapple ends, the target is restrained.

Claw. Melee Weapon Attack:

Swallow. The Balor makes one bite attack against a Large or smaller creature it is grappling. If the attack hits, the target takes the bite's damage, the target is swallowed, and the grapple ends. While swallowed, the creature is restrained , it has total cover against attacks and other effects outside the Balor , and it takes 56 (16d6) Fire damage at the start of each of the Balor turns.

If the Balor  takes 60 damage or more on a single turn from a creature inside it, the Balor must succeed on a DC 20 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the Balor . If the Balor dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 30 feet of movement, exiting prone .