Armor Class 15 (natural armor)
Hit Points 66 (12d8 + 12)
Speed 30 ft., fly 60 ft.

Saving Throws
Skills Deception +9, Insight +5, Perception +5, Persuasion +9, Stealth +7
Damage Resistances cold, fire, lightning, poison; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities
Condition Immunities
Senses darkvision 60 ft., passive Perception 15
Languages Abyssal, Common, Infernal, telepathy 60 ft.
Challenge 4 (1100 XP)

Telepathic Bond. The fiend ignores the range restriction on its telepathy when communicating with a creature it has charmed. The two don’t even need to be on the same plane of existence.

Shapechanger. The fiend can use its action to polymorph into a Small or Medium humanoid, or back into its true form. Without wings, the fiend loses its flying speed. Other than its size and speed, its statistics are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.

Actions

Claw (Fiend Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.

Charm. One humanoid the fiend can see within 30 feet of it must succeed on a DC 15 Wisdom saving throw or be magically charmed for 1 day. The charmed target obeys the fiend’s verbal or telepathic commands. If the target suffers any harm or receives a suicidal command, it can repeat the saving throw, ending the effect on a success. If the target successfully saves against the effect, or if the effect on it ends, the target is immune to this fiend’s Charm for the next 24 hours. The fiend can have only one target charmed at a time. If it charms another, the effect on the previous target ends.

Draining Kiss. The fiend kisses a creature charmed by it or a willing creature. The target must make a DC 15 Constitution saving throw against this magic, taking 32 (5d10 + 5) psychic damage on a failed save, or half as much damage on a successful one. The target’s hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Etherealness. The fiend magically enters the Ethereal Plane from the Material Plane, or vice versa.

Armor Class 15 (natural armor)
Hit Points 104 (11d10 + 44)
Speed 40 ft., fly 60 ft.

Saving Throws Dex +5, Wis +4, Cha +2
Skills 
Damage Resistances cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities poisoned
Senses darkvision 120 ft., passive Perception 11
Languages Abyssal, telepathy 120 ft.
Challenge 6 (2300 XP)

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

Actions

Multiattack. The vrock makes two attacks: one with its beak and one with its talons.

Beak. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) piercing damage.

Talons. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 14 (2d10 + 3) slashing damage.

Spores (Recharge 6). A 15-foot-radius cloud of toxic spores extends out from the vrock. The spores spread around corners. Each creature in that area must succeed on a DC 14 Constitution saving throw or become poisoned. While poisoned in this way, a target takes 5 (1d10) poison damage at the start of each of its turns. A target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. Emptying a vial of holy water on the target also ends the effect on it.

Stunning Screech (1/Day). The vrock emits a horrific screech. Each creature within 20 feet of it that can hear it and that isn’t a demon must succeed on a DC 14 Constitution saving throw or be stunned until the end of the vrock’s next turn.

Armor Class 16 (natural armor)
Hit Points 110 (13d8 + 52)
Speed 40 ft.

Saving Throws 
Skills Deception +10, Insight +8
Damage Resistances 
Damage Immunities bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities 
Senses darkvision 60 ft., passive Perception 13
Languages Common, Infernal
Challenge 13 (10000 XP)

Limited Magic Immunity. The rakshasa can’t be affected or detected by spells of 6th level or lower unless it wishes to be. It has advantage on saving throws against all other spells and magical effects.

Innate Spellcasting. The rakshasa’s innate spellcasting ability is Charisma (spell save DC 18, +10 to hit with spell attacks). The rakshasa can innately cast the following spells, requiring no material components: At will: ““, ““, ““, ““ 3/day each: ““, ““, ““, ““, s_uggestion” show=““] 1/day each: ““, ““, ““, ““

Actions

Multiattack. The rakshasa makes two claw attacks.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) slashing damage, and the target is cursed if it is a creature. The magical curse takes effect whenever the target takes a short or long rest, filling the target’s thoughts with horrible images and dreams. The cursed target gains no benefit from finishing a short or long rest. The curse lasts until it is lifted by a ““ spell or similar magic.

Armor Class 13 (natural armor)
Hit Points 68 (8d10 + 24)
Speed 60 ft., fly 90 ft.

Saving Throws 
Skills 
Damage Resistances 
Damage Immunities fire
Condition Immunities 
Senses passive Perception 11
Languages understands Abyssal, Common, and Infernal but can't speak
Challenge 3 (700 XP)

Confer Fire Resistance. The nightmare can grant resistance to fire damage to anyone riding it.

Illumination. The nightmare sheds bright light in a 10- foot radius and dim light for an additional 10 feet.

Actions

Hooves. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage plus 7 (2d6) fire damage.

Ethereal Stride. The nightmare and up to three willing creatures within 5 feet of it magically enter the Ethereal Plane from the Material Plane, or vice versa.

Armor Class 18 (natural armor)
Hit Points 180 (19d10 + 76)
Speed 40 ft.

Saving Throws Dex +7, Con +9, Wis +7, Cha +9
Skills 
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks that aren't silvered
Damage Immunities cold, fire, poison
Condition Immunities poisoned
Senses blindsight 60 ft., darkvision 120 ft., passive Perception 12
Languages Infernal, telepathy 120 ft.
Challenge 14 (11500 XP)

Devil’s Sight. Magical darkness doesn’t impede the devil’s darkvision.

Armor Class 18 (natural armor)
Hit Points 189 (18d10 + 90)
Speed 40 ft.

Saving Throws Str +9, Con +10, Wis +8, Cha +10
Skills 
Damage Resistances cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities poisoned
Senses truesight 120 ft., passive Perception 13
Languages Abyssal, telepathy 120 ft.
Challenge 16 (15000 XP)

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

Magic Weapons. The marilith’s weapon attacks are magical.

Reactive. The marilith can take one reaction on every turn in a combat.

Actions

Multiattack. The marilith makes seven attacks: six with its longswords and one with its tail.

Longsword. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Tail. Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 15 (2d10 + 4) bludgeoning damage. If the target is Medium or smaller, it is grappled (escape DC 19). Until this grapple ends, the target is restrained, the marilith can automatically hit the target with its tail, and the marilith can’t make tail attacks against other targets.

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

Reactions

Parry. The marilith adds 5 to its AC against one melee attack that would hit it. To do so, the marilith must see the attacker and be wielding a melee weapon.

Armor Class 19 (natural armor)
Hit Points 300 (24d10 + 168)
Speed 30 ft., fly 60 ft.

Saving Throws Dex +8, Con +13, Wis +10
Skills 
Damage Resistances cold; bludgeoning, piercing, and slashing from nonmagical attacks that aren't silvered
Damage Immunities fire, poison
Condition Immunities poisoned
Senses truesight 120 ft., passive Perception 14
Languages Infernal, telepathy 120 ft.
Challenge 20 (25000 XP)

Fear Aura. Any creature hostile to the pit fiend that starts its turn within 20 feet of the pit fiend must make a DC 21 Wisdom saving throw, unless the pit fiend is incapacitated. On a failed save, the creature is frightened until the start of its next turn. If a creature’s saving throw is successful, the creature is immune to the pit fiend’s Fear Aura for the next 24 hours.

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

Magic Weapons. The pit fiend’s weapon attacks are magical.

Innate Spellcasting. The pit fiend’s spellcasting ability is Charisma (spell save DC 21). The pit fiend can innately cast the following spells, requiring no material components: At will: ““, ““ 3/day each: ““, ““

Actions

Multiattack. The pit fiend makes four attacks: one with its bite, one with its claw, one with its mace, and one with its tail.

Bite. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 22 (4d6 + 8) piercing damage. The target must succeed on a DC 21 Constitution saving throw or become poisoned. While poisoned in this way, the target can’t regain hit points, and it takes 21 (6d6) poison damage at the start of each of its turns. The poisoned target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 17 (2d8 + 8) slashing damage.

Mace. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) bludgeoning damage plus 21 (6d6) fire damage.

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

Armor Class 7
Hit Points 13 (3d8)
Speed 15 ft.

Saving Throws 
Skills 
Damage Resistances cold
Damage Immunities fire, poison
Condition Immunities charmed, frightened, poisoned
Senses darkvision 120 ft., passive Perception 10
Languages understands Infernal but can't speak
Challenge 0 (10 XP)

Devil’s Sight. Magical darkness doesn’t impede the lemure’s darkvision.

Hellish Rejuvenation. A lemure that dies in the Nine Hells comes back to life with all its hit points in 1d10 days unless it is killed by a good-aligned creature with a ““ spell cast on that creature or its remains are sprinkled with holy water.

Actions

Fist. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 2 (1d4) bludgeoning damage.

Armor Class 18 (natural armor)
Hit Points 184 (16d10 + 96)
Speed 20 ft., fly 30 ft.

Saving Throws Con +11, Int +9, Wis +6, Cha +7
Skills 
Damage Resistances cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities poisoned
Senses truesight 120 ft., passive Perception 11
Languages Abyssal, telepathy 120 ft.
Challenge 13 (10000 XP)

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

Actions

Multiattack. The nalfeshnee uses Horror Nimbus if it can. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 32 (5d10 + 5) piercing damage.

Claw. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 15 (3d6 + 5) slashing damage.

Horror Nimbus (Recharge 5–6). The nalfeshnee magically emits scintillating, multicolored light. Each creature within 15 feet of the nalfeshnee that can see the light must succeed on a DC 15 Wisdom saving throw or be 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 nalfeshnee’s Horror Nimbus for the next 24 hours.

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

Armor Class 17 (natural armor)
Hit Points 112 (15d8 + 45)
Speed 30 ft.

Saving Throws 
Skills Deception +7, Insight +6, Perception +6, Stealth +6
Damage Resistances cold, fire; bludgeoning, piercing, and slashing from nonmagical attacks not made with silvered weapons
Damage Immunities 
Condition Immunities charmed
Senses darkvision 120 ft., passive Perception 16
Languages Abyssal, Common, Infernal, Primordial
Challenge 5 (1800 XP)

Innate Spellcasting. The hag’s innate spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). She can innately cast the following spells, requiring no material components: At will: ““, ““ 2/day each: ““ (self only), ““, ““

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

Actions

Claws (Hag Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Change Shape. The hag magically polymorphs into a Small or Medium female humanoid, or back into her true form. Her statistics are the same in each form. Any equipment she is wearing or carrying isn’t transformed. She reverts to her true form if she dies.

Etherealness. The hag magically enters the Ethereal Plane from the Material Plane, or vice versa. To do so, the hag must have a ““ in her possession.

Nightmare Haunting (1/Day). While on the Ethereal Plane, the hag magically touches a sleeping humanoid on the Material Plane. A ““ spell cast on the target prevents this contact, as does a ““ spell or similar magic.