Umibōzu
There is no greater threat to seafaring ships than the Umibōzu. Native to the coastline of northeast China and the seas surrounding the Islands of Japan, the Umibōzu is a malevolent giant that rises from the depths to demand ransom from passing ships (usually a portion of the ship’s cargo) in exchange for safe passage. However, the Umibōzu is lying (DC 14 Insight), since it will usually destroy ships even if they comply with these demands.
Massive Size. The Umibōzu is said to range in size, with younger ones appearing around the size of a hill giant (SRD) and adults growing to tower above the tallest storm giants. They are often described as having ambiguous forms, with their faces and bodies usually shrouded in darkness and partially submerged in the sea.
Inscrutable Motivations. The Umibōzu is said to attack ships during calm seas in broad daylight (with its Storm Aura quickly reversing these conditions as it appears); however, aside from this detail, there seems to be little reason why the Umibōzu attacks one ship and lets another pass. Its motivations seem completely random,
Umibōzu
Gargantuan giant, Neutral Evil
Armor Class: 14 (natural armor)
Hit Points: 310 (20d20 + 100)
Speed: 60 ft., swim 40 ft.
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 20 (+5) | 10 (+0) | 20 (+5) | 9 (-1) | 10 (+0) | 19 (+4) |
Saving Throws: Str +11, Con +11
Senses: darkvision 120 ft., passive perception 13
Languages: Chinese, Japonic
Challenge: 17 (18,000 XP) Proficiency: +6
Features
Amphibious: The Umibōzu can breathe air and water.
Easily Confused: If the Umibōzu is confronted with a riddle, puzzle, magic trick, logical paradox, or optical illusion (such as a barrel with no bottom), it must succeed on a DC 16 Intelligence saving throw or become Stunned for 1 hour. While stunned in this way, the Umibōzu cannot move or take actions other than to mutter to itself in confusion. The Umibōzu remains confused for 1 hour, or until it takes any damage.
Magic Resistance: The Umibōzu has advantage on saving throws against spells and other magical effects.
Storm Aura: When the Umibōzu rises above the surface of the water, its presence begins to affect the environment around it out to a radius of 5 miles. Over the course of 10 minutes the sky slowly grows darker as even moonlight fades and the weather gradually turns stormy and violent. If the Umibōzu is killed or returns to the sea, the weather and sky return to normal after 1d4 minutes.
attacking crews of all races and religions, from merchant vessels to imperial warships.
Logical Vulnerability. A common superstition shared amongst sailors in Chinese and Japanese ports is that all ships should carry a barrel with no bottom in its cargo. According to stories from survivors, if the Umibōzu is given a bottomless barrel as ransom, it will become confused for long enough that a ship can make its escape. Logical inconsistencies (such as riddles) seem to have the same effect on the Umibōzu (provided it can hear and understand them).
Actions
Multiattack: The Umibōzu can use its frightful presence. It then makes two Slam attacks.
Slam: Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 16 (2d10 + 5) bludgeoning damage.
Frightful Presence: Each creature of the Umibōzu’s choice within 120 feet of it and aware of it must succeed on a DC 18 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself with a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the Umibōzu’s Frightful Presence for the next 24 hours.
Legendary Actions
The Umibōzu can take 3 legendary actions, choosing from the options below. Only one legendary action option may be used at a time, and only at the end of another creature’s turn. The Umibōzu regains spent legendary actions at the start of its turn.
Detect: The Umibōzu makes a Perception check.
Wave (costs 2 actions): A wave crests across the surface of the ocean, striking water vehicles within a 60-foot square, centered on a point of the Umibōzu’s choice within 120 feet. Each vehicle in this area that is touching the water must succeed on a DC 16 Strength saving throw or roll on its “Mishap” table, if it has one.
Call Lightning (costs 3 actions): Three bolts of lightning arc from the stormy skies above, striking three points of the Umibōzu’s choice within 150 feet of it. Each creature within 5 feet of one of these points must make a DC 18 Dexterity saving throw. A creature takes 17 (3d10) lightning damage on a failed save, or half as much damage on a successful one.
Source attribution and license
Silk Road's Guide to Seafaring, printed pages 208.