Ilchon Bopsa 일촌법사

Large beast (mythic), lawful neutral

Armor Class 18 (natural armor)

Hit Points 210 (20d10 + 100)

Speed 25 ft., climb 30 ft., swim 40 ft.

STR 17 (+3) · DEX 14 (+2) · CON 20 (+5) · INT 18 (+4) · WIS 16 (+3) · CHA 17 (+3)

Saving Throws Con +10, Int +9, Wis +8

Skills Arcana +9, History +9, Insight +8, Perception +8, Stealth +7, Survival +8

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

Damage Immunities poison

Condition Immunities poisoned

Senses darkvision 120 ft., passive Perception 18

Languages Common, Aquan, Sylvan, Thieves’ Cant; telepathy 120 ft.

Challenge 14 (11,500 XP)

Traits

Amphibious. Ilchon Bopsa can breathe air and water.

Keen Smell. Ilchon Bopsa has advantage on Wisdom (Perception) checks that rely on smell.

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

Water Mastery. While Ilchon Bopsa or its target is touching water, its attacks deal an extra 5 (1d10) bludgeoning damage and creatures it knocks prone must spend 15 ft. of movement, not 10, to stand.

Innate Spellcasting. Ilchon Bopsa’s innate spellcasting ability is Intelligence (spell save DC 17, +9 to hit). It requires no components to cast the following spells:

At will: create or destroy water (PHB, p. 229/258), shape water (XGE, p. 164)

3/day: tidal wave (XGE, p. 168), wall of water (XGE, p. 170), control water (PHB, p. 227/256)

1/day: tsunami (PHB, p. 284/336)

Actions

Multiattack. Ilchon Bopsa makes two attacks: one with Bite and one with Tail Lash, or two Tail Lash attacks.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 3) piercing damage plus 7 (2d6) poison damage.

Tail Lash. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 18 (2d12 + 3) bludgeoning damage, and the target must succeed on a DC 18 Strength saving throw or be pushed up to 10 ft. and knocked prone.

Hydro-Bolt. Ranged Spell Attack: +9 to hit, range 120 ft., one target. Hit: 22 (4d8 + 4) bludgeoning damage, and the target must succeed on a DC 18 Strength saving throw or be knocked prone.

Deluge (Recharge 5–6). Whirling its preternatural tail, Ilchon Bopsa unleashes a roaring 60-foot cone of water. Each creature in the cone must make a DC 18 Dexterity saving throw, taking 45 (10d8) bludgeoning damage and being knocked prone on a failed save, or half as much damage on a successful one. The area becomes difficult terrain (water) for 1 minute.

Bonus Actions

Tail Cyclone. Ilchon Bopsa spins its tail at lightning speed until the start of its next turn. During this time ranged weapon attacks against it are made with disadvantage, and Water Mastery’s extra damage increases to 10 (2d10).

Reactions

Water Shield. When Ilchon Bopsa is hit by an attack, it conjures a splash of water, gaining resistance to that attack’s damage and pushing itself up to 10 ft. in any direction.

Lore

A rat over ten thousand years old, possessed of powerful magic; a flick of its tail conjures a torrent that

The Ten-Thousand-Year Rat is a creature from Korean mythology, where an animal’s great age is directly linked to the magical powers it acquires. Legend says this rat is one of the mighty beings that serve the Great Thief and dwells in his palace on a remote island.

It’s not the only animal of its kind. The rat belongs to a unique hierarchy of ancient beasts that also includes the Thousand-Year Bear, the Thousand-Year Fox, and the Ten-Thousand-Year Tiger. Each species gains a distinct power whose strength matches its age.

From Korean Bestiary 5E, p. 64 · Fern Flower Press