Chihaguk Daejeok 지하국대적

Huge monstrosity, lawful evil

Armor Class 18 (natural armor; see Vulnerable Scales)

Hit Points 230 (20d12 + 100)

Speed 40 ft., climb 30 ft.

STR 24 (+7) · DEX 12 (+1) · CON 21 (+5) · INT 14 (+2) · WIS 16 (+3) · CHA 18 (+4)

Saving Throws Con +11, Wis +9, Cha +10

Skills Deception +10, Insight +9, Intimidation +10, Perception +9

Damage Resistances bludgeoning, piercing, and slashing from non-magical attacks

Damage Immunities poison

Condition Immunities charmed, poisoned

Senses darkvision: 120 ft., passive Perception 19

Languages Common, Giant, Undercommon, telepathy 120 ft.

Challenge 16 (15,000 XP)

Traits

Nine Heads. Chihaguk Daejeok has nine heads. While it has more than one head, it has advantage on saving throws against being blinded, deafened, stunned, or knocked unconscious, and it can’t be surprised. It can make up to three Bite attacks on its turn (see Multiattack).

Severing a Head. When Chihaguk Daejeok takes 30 or more slashing damage during a single turn from a creature within 5 feet, one of its heads is severed at the end of that turn (choose randomly). For each head lost, it loses one Bite attack.

Reattaching Heads. At the start of its turn, Chihaguk Daejeok reattaches one severed head, regaining 20 hit points, unless the stump is coated with at least a handful of loose soil, sand, or ash (an adjacent creature can use its action to do so). If all nine heads are severed, the monster dies.

Vulnerable Scales. A hand-sized golden scale lies beneath each of Chihaguk Daejeok’s armpits (two in total). A creature can target a scale by declaring so before it makes a melee attack; the attack roll is made with disadvantage. If the attack hits and deals at least 15 damage, that scale is destroyed. While at least one vulnerable scale remains, the monster regains 15 hit points at the start of each of its turns and can use Reattaching Heads. If both scales are destroyed, its AC drops to 16, it loses its Regeneration and Reattaching Heads traits, and it can’t benefit from the Magic Resistance trait.

Magic Resistance. While it has at least one vulnerable scale, Chihaguk Daejeok has advantage on saving throws against spells and other magical effects.

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

Actions

Multiattack. Chihaguk Daejeok makes three attacks: up to three with Bite (one per remaining head, maximum three) and one with Tail Slam.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 7) piercing damage plus 7 (2d6) poison damage.

Kidnap (Recharge 5–6). Chihaguk Daejeok makes one Bite attack against a Medium or smaller creature it is grappling. If the attack hits, the target takes an extra 18 (4d8) poison damage and must succeed on a DC 17 Constitution saving throw or fall unconscious for 1 minute (the target wakes if it takes damage or another creature uses an action to shake it awake). While unconscious, the target is automatically grappled and carried by the monster.

Reactions

Parrying Head. When a creature Chihaguk Daejeok can see hits it with a melee attack, it subtracts 5 from the damage dealt.

Legendary Actions

Chihaguk Daejeok 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. It regains spent legendary actions at the start of its turn.

Move. Chihaguk Daejeok moves up to half its speed.

Bite. Chihaguk Daejeok makes one Bite attack.

Dread Roar (Costs 2 Actions). Each creature of Chihaguk Daejeok’s choice within 30 feet that can hear it must succeed on a DC 18 Wisdom saving throw or be frightened for 1 minute. A frightened creature can repeat the save at the end of each of its turns, ending the effect on itself on a success.

Reattach Head (Costs 3 Actions). If a head has been severed and its neck stump isn’t coated with sand, ash, or soil, Chihaguk Daejeok reattaches it, regaining 20 hit points. This option can’t be taken if both vulnerable scales are destroyed.

Lair Actions

On initiative count 20 (losing initiative ties) while in his underground palace, Chihaguk Daejeok can invoke the following effects:

Grasping Roots. Roots erupt in a 20-foot square he can see. Each creature there must make a DC 18 Strength save or be restrained until the next round.

Rolling Boulder. A massive stone tumbles along a 30-foot line. Creatures in the line make a DC 17 Dexterity save, taking 21 (6d6) bludgeoning damage on a failure, or half on a success.

Shadow Veil. Magical darkness (as the *darkness* spell) fills a 15-foot radius around a point he chooses, lasting until the next round.

Lore

A nine-headed terror from the Underworld that frightens villagers and abducts women.

Chihaguk Daejeok (지하국대적), literally “the Great Foe of the Underground Kingdom,” is one of the best-known monsters in Korean folklore. He appears as the chief antagonist in countless legends and tales, usually portrayed as a mighty ruler of the underworld who habitually abducts women.

His most striking feature is his nine heads, a detail that highlights both his monstrosity and his overwhelming power. Unlike the Greek Hydra, whose severed heads multiply, Chihaguk Daejeok’s heads do not grow back on their own. Instead, he uses magic to reattach a severed head to his body. Beyond his many heads, he is described as gigantic—over ten feet tall—comparable to other Korean giants such as Magohalmi (마고할미) and Jangin (장인). But his role differs: while Magohalmi is a creator goddess and Jangin is a man-eater, Chihaguk Daejeok is an invader and kidnapper of beautiful women. His colossal size not only poses a physical threat, it also underscores his status as a fearsome sovereign of the underworld, far beyond ordinary human limits.

From Korean Bestiary 5E, p. 22 · Fern Flower Press