AC 18 (natural armor)
HP 220 (21d10 + 105; bloodied 110)
Speed 40 ft.
Proficiency +5; Maneuver DC 19
Saving Throws Str +10, Dex +11, Con +10, Wis +9, Cha +10
Damage Resistances cold, fire, lightning; damage from nonmagical weapons
Damage Immunities poison
Condition Immunities poisoned
Senses truesight 120 ft., passive Perception 14
Languages Abyssal, telepathy 120 ft.
Chaotic Evil. The marilith radiates a Chaotic and Evil aura.
Magic Resistance. The marilith has advantage on saving throws against spells and magical effects.
ACTIONS
Multiattack. The marilith makes six attacks with its longswords.
Longsword. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage.
BONUS ACTIONS
Tail. Melee Weapon Attack: +10 to hit, reach 10 ft., one creature. Hit: 10 (2d4 + 5) bludgeoning damage, and the target is grappled (escape DC 19).
Teleport. The marilith magically teleports up to 120 feet to an unoccupied space it can see.
REACTIONS
Reactive Teleport. When the marilith is hit or missed by a ranged attack, it uses Teleport. If it teleports within 5 feet of a creature, it can attack with its tail.
Combat
The marilith starts combat by engaging the strongest melee opponent, focusing its attacks against that enemy. It uses its tail to prevent its enemy from retreating. If troubled by ranged attacks, the marilith uses Reactive Teleport to move next to the ranged attacker and grapple them, so that it can attack the target with its longswords on its next turn. If reduced to 55 hit points or fewer, it uses Teleport to escape.
Demon Names
Abigor, Aborag, Agoraxas, Algalar, Ana-Sepiya, Arcanax, Argenthrixus, Ashban, Brezremith, Caim, Carn, Carnifex, Gall, Hacari, Ignax, Ildramath, Iritra, Lachirax, Maggoth, Malfias, Milviash, Moloth, Morza, Namazeu, Razortail, Sarzan, Serechor, Suroth, Tehezu, Uzuzzu, Velavis, Velgizich, Wreak, Zugor, Zuthis
Legends and Lore
With an Arcana or Religion check, characters can learn the following:
DC 10 Demons are fiends spawned from the Abyss. They are creatures of pure chaos: even the most intelligent demon can’t be reasoned with.
DC 15 Poison can’t adversely affect a demon’s alien physiology. They shrug off much of the damage caused by cold, fire, lightning, and mundane weapons.
DC 20 The most powerful demons are even more resilient. They entirely ignore the effects of many magic spells.
With the lower body of a serpent and six sword-wielding arms, the marilith is an image of death incarnate. Of all the demons spawned from the Abyss, mariliths are perhaps the most adaptable. They can serve as captivating leaders, skilled tacticians, deadly assassins, or advisors to more powerful fiends, such as a balor or demon lords. Trying to reason with a marilith, however, is folly. Mariliths are creatures of chaos; if they employ logic, it is only because doing so allows them to slaughter their enemies more effectively.
1–3 Committing acts of mindless destruction (setting a fire, uprooting trees, defiling a holy site)
4 Trapped in an abandoned summoning circle
5 Pacing the far side of a magic mirror or planar gate, waiting to be released
6 Mangling the corpse of a recent kill
7 Guarding or patrolling, under the control of a summoner
8 Using napkins and rusted cutlery to dine on humanoid corpses
9 Drawn to you by the secret holy or unholy power of one of your magic items
10 if you let it live, it promises to harm one of your enemies
1 Pained screams accompanied by guttural laughter
2 Residual negative emotions (envy, paranoia, rage) subtly influence the area’s inhabitants
3 Horribly misshapen animals, born with extra legs, eyes, or heads
4 The remains of another monster, torn limb from limb
5 A human corpse; its face is frozen in an expression of horror
6 Clawed footprints
Demons are native to the Abyss but can threaten any part of the world if summoned or by bursting through poorly-sealed arcane gates.
CR 3–4 horde demon ; shadow demon ; quasit with 1 to 3 death dogs
CR 5–10 glabrezu ; hezrou ; vrock ; 2 or 3 horde demons ; 2 shadow demons ; shadow demon with 1d4 shadows
Treasure 1 warhammer (named Night Terror; its wielder is rattled while in darkness)
CR 11–16 horde demon band ; marilith ; nalfeshnee ; glabrezu with 1 or 2 horde demons ; hezrou with 1d6 + 2 ghouls ; 3 or 4 shadow demons
Treasure 2 scimitar (named Wrath; intelligent, Lawful Evil, with Intelligence, Wisdom and Charisma scores of 12)
CR 17–22 balor ; 2 glabrezu ; 3 vrocks ; horde demon band with cambion , hezrou , or vrock
Treasure gold demon idol (7,500 gp), 2 bottles containing invisible wine that act as potions of invisibility , spell scrolls of contact other plane and dominate person , demon armor
CR 23–30 balor general ; balor or marilith with horde demon band ; marilith with 2 spirit nagas
Treasure massive ruby (25,000 gp) that contains a soul trapped by the magic jar spell, spell scrolls of magic jar and plane shift , 3 arrows of celestial slaying , 2 longsword (named Storm Claw; its wielder can cast lightning bolt with no components once per long rest, saving throw DC 18)
CR 31+ balor general with horde demon band , marilith , or nalfeshnee ; balor with 1d4 + 1 vrocks ; marilith with 3 or 4 hezrous
Treasure gemmed black iron war horn (25,000 gp), gemmed dragonbone crown (25,000 gp), 4 elemental gems (water) , Ioun stone of leadership , vorpal sword
Fiends are evil-aligned creatures from Hell, the Abyss, and other cursed realms. Most fiends are demons and devils, each of which have their own subtypes and hierarchies. Some fiends, such as hell hounds , are neither demons nor devils.