Imugi 이무기

Huge dragon, typically neutral (see Variants)

Armor Class 19 (natural armor)

Hit Points 231 (22d12 + 88)

Speed 40 ft., swim 60 ft.

STR 23 (+6) · DEX 14 (+2) · CON 19 (+4) · INT 16 (+3) · WIS 18 (+4) · CHA 18 (+4)

Saving Throws Dex +8, Con +10, Wis +10, Cha +10

Skills History +9, Insight +10, Perception +16, Religion +9

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

Condition Immunities charmed, frightened (see Variants)

Senses blindsight 60 ft., darkvision 120 ft., passive Perception 26

Languages Common, Draconic, Aquan, telepathy 120 ft.

Challenge 14 (11,500 XP)

Traits

Amphibious. The imugi can breathe air and water.

Born of the Deep. While submerged, the imugi has advantage on Dexterity saving throws and on attack rolls against creatures that lack a swim speed.

Hardened Scales. Critical hits against the imugi become normal hits.

Yeouiju Bearer. Embedded in the imugi’s forehead is an unripe pearl. While it lives, the imugi can innately cast spells (spell save DC 18, +10 to hit with spell attacks):

At will: create or destroy water (PHB, p. 229/258), fog cloud (PHB, p. 243/276)

3/day each: control water (PHB, p. 227/256), lightning bolt (PHB, p. 255/292), wall of water (XGE, p. 170)

1/day: control weather (PHB, p. 228/257)

Actions

Multiattack. The imugi makes two Bite attacks and one Tail attack.

Bite. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 6) piercing damage plus 10 (3d6) poison damage.

Tail. Melee Weapon Attack: +11 to hit, reach 20 ft., one target. Hit: 21 (3d8 + 6) bludgeoning damage. If the target is a creature, it must succeed on a DC 19 Strength saving throw or be pushed up to 15 ft. and knocked prone.

Constrict. Melee Weapon Attack: +11 to hit, reach 10 ft., one Large or smaller creature. Hit: 17 (2d8 + 6) bludgeoning damage, and the target is grappled (escape DC 19). Until this grapple ends, the target is restrained, and the imugi can’t constrict another target.

Tidal Breath (Recharge 5–6). The imugi exhales a 60-foot-long, 10-foot-wide torrent of crushing water. Each creature in that line must make a DC 18 Strength saving throw, taking 45 (10d8) bludgeoning damage on a failed save, or half as much on a success. A creature that fails is also knocked prone.

Bonus Actions

Sudden Dive. If the imugi is within 10 ft. of a body of water large enough to contain it, it can move up to its swim speed into that water without provoking opportunity attacks.

Reactions

Scale Deflection. When the imugi is hit by an attack it can see, it halves the attack’s damage.

Variants: Noble & Fallen

Choose one or roll a d4 when the creature is first encountered.

1–2 — Noble Imugi (lawful neutral). Ignores the frightened condition and won’t attack unless its sanctum is violated. While a creature within 60 ft. sincerely praises it as a “dragon,” the imugi has advantage on all ability checks and saving throws and can’t be surprised.

3–4 — Fallen Imugi (chaotic evil). Has advantage on attack rolls against creatures it has damaged in the same combat. Creatures that call it a “snake” within 60 ft. must succeed on a DC 18 Wisdom saving throw or be frightened of the imugi for 1 minute (save ends at end of each of the creature’s turns).

Lore

A serpent that failed to become a true dragon. Sours in temperament; often preys on livestock

Few creatures in Korean folklore evoke such mixed feelings as the Imugi. It is not just a monster but a tragic, multifaceted being caught between the mortal world and the realm of gods. Unlike the true dragon—an image of power, wisdom, and celestial order—an Imugi is stuck on the road to its final transformation. It stands for struggle, patience, and the bitter possibility of last-second failure.

The word Imugi usually means a gigantic serpent that has not yet become a dragon. In Korean the term is often interchangeable with iryong (이룡), literally “hornless dragon.” The missing horns are everything: they mark its unfinished status. Because of this, the creature is often portrayed as driven by rage and resentment.

From Korean Bestiary 5E, p. 66 · Fern Flower Press