Umbral Serpent | Free 5e & PF2e Monster

Written by Owen Davies

The umbral serpent is an alternative promotion for voidsworn. The form of the umbral serpent is designated for those who have made significant strides in their understanding and utility of deceit. These large serpents are known to hide among the shadows, only their red eyes visible in the darkness.

Versions for both 5e and Pathfinder 2e are included.

If you're looking for more monsters like this or other 5e and PF2e resources, check out our entire collection of Lair Magazine issues. This particular monster came from the November 2023 issue, Fiends & Flames, where you can find even more fiendish creatures!

Umbral Serpent - 5e

Large fiend (devil), lawful evil

Armor Class 16 (natural armor)

Hit Points 97 (13d10 + 26)

Speed 30 ft.

Saving Throws Dex +7, Int +5, Cha +6

Skills Arcana +5, Perception +6, Stealth +7

Damage Immunities fire, poison

Damage Resistances cold, necrotic; bludgeoning, piercing, and slashing from nonmagical attacks that aren’t silvered.

Condition Immunities poisoned

Senses darkvision 120 ft., passive Perception 16

Languages Infernal, telepathy 120 ft.

Challenge 9 (5,000 XP)   Proficiency Bonus +4             

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

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

Shadowed Form. Any creature who starts their turn within 5 feet of the umbral serpent must succeed on a DC 16 Constitution saving throw or be blinded until the start of their next turn.

Shadow Stealth. While in dim light or darkness, the umbral serpent can take the Hide action as a bonus action.

Actions

Multiattack. The umbral serpent uses Constrictive Darkness if it can. Then it makes two attacks: one bite attack and one tail attack.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage, and the target must make a DC 16 Constitution saving throw. On a failure, the target takes 14 (4d6) poison damage and 14 (4d6) necrotic damage. Additionally, the target is poisoned for the next 24 hours. On a success, the target takes half the damage and is not poisoned.

Tail. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 8 (1d8 + 4) slashing damage and 7 (2d6) poison damage.

Constrictive Darkness (Recharge 5-6). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage, and the target is grappled (escape DC 18). Until the grapple ends, the creature is restrained, and the umbral serpent can’t constrict another target. If a creature starts its turn grappled, it takes 14 (4d6) necrotic damage.

Hidden Strike (Recharge 6). While in dim light or darkness, the umbral serpent can teleport to another point it can see within 60 feet that is also in dim light or darkness. From its new position, all creatures within 5 feet of the umbral serpent must succeed a DC 18 Dexterity saving throw or take 35 (10d6) necrotic damage.

Umbral Serpent - Pathfinder 2

Creature 10, LE, Large, Devil, Fiend

Perception +20; greater darkvision

Languages Infernal; telepathy 60 ft.

Skills Acrobatics +22, Arcana +17, Intimidation +19, Stealth +22, Survival +19

Str +5, Dex +7, Con +6, Int +3, Wis +4, Cha +5

—

AC 28; Fort +19, Ref +22, Will +16; +1 status to all saves vs. magic

HP 215; Immunities fire; Resistances physical 13 (except silver), negative 13, cold 7; Weaknesses good 13

—

Speed 25 feet

Melee [one action] bite +23 (evil), Damage 1d10+11 piercing plus 1d10 evil and umbral poison.

Melee [one action] constrict +20 (evil, agile, grapple), Damage 2d12+13 bludgeoning, and the target is restrained. The umbral serpent cannot use this action again unless it releases its target.

Dark Steps [one-action] The umbral serpent strides and hides or steps and hides.

Hidden Strike [two actions] The umbral serpent teleports to a point it can see within 60 feet. Both its starting and target point must be in dim light or darkness. All creatures within 5 feet of its target must make a DC 26 Basic Reflex save or take 6d6 negative damage.

Umbral Poison (poison) Saving Throw DC 26 Fortitude; Maximum Duration One hour; Stage 1 1d6 poison damage (10 minutes); Stage 2 2d6 poison damage and blinded (10 minutes)

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