# [Leviathan](Rules\Source\bestiary\elemental/leviathan-mpmm.md)
*Source: Mordenkainen Presents: Monsters of the Multiverse p. 171*
A leviathan is an immense creature that acts as a force of nature, dragging ships down to the ocean's depths and washing away coastal settlements. When called forth, a leviathan arises from a large body of water and takes on the form of a gigantic serpent.
Usually found only on the Elemental Plane of Water, a leviathan sometimes swims through a portal to another world, where tritons, sea elves, and other aquatic folk attempt to contain it. Nihilistic cults have also been known to perform arduous rituals to summon a leviathan to a world, with the aim of using the creature to destroy coastal communities. Those cultists often consider it a blessing to drown themselves in the elemental's waters.
```statblock
"name": "Leviathan (MPMM)"
"size": "Gargantuan"
"type": "elemental"
"alignment": "Typically Neutral"
"ac": !!int "17"
"hp": !!int "328"
"hit_dice": "16d20 + 160"
"modifier": !!int "7"
"stats":
- !!int "27"
- !!int "24"
- !!int "30"
- !!int "2"
- !!int "18"
- !!int "17"
"speed": "40 ft., swim 120 ft."
"saves":
- "wisdom": !!int "10"
- "charisma": !!int "9"
"damage_resistances": "bludgeoning, piercing, slashing from nonmagical attacks"
"damage_immunities": "acid, poison"
"condition_immunities": "[exhaustion](/Rules/Source/conditions.md#Exhaustion), [grappled](/Rules/Source/conditions.md#Grappled),\
\ [paralyzed](/Rules/Source/conditions.md#Paralyzed), [petrified](/Rules/Source/conditions.md#Petrified),\
\ [poisoned](/Rules/Source/conditions.md#Poisoned), [prone](/Rules/Source/conditions.md#Prone),\
\ [restrained](/Rules/Source/conditions.md#Restrained), [stunned](/Rules/Source/conditions.md#Stunned)"
"senses": "[darkvision](/Rules/Source/senses.md#Darkvision) 60 ft., passive Perception\
\ 14"
"languages": ""
"cr": "20"
"traits":
- "desc": "If the leviathan fails a saving throw, it can choose to succeed instead."
"name": "Legendary Resistance (3/Day)"
- "desc": "If the leviathan takes 50 cold damage or more during a single turn, the\
\ leviathan partially freezes; until the end of its next turn, its speeds are\
\ reduced to 20 feet, and it makes attack rolls with disadvantage."
"name": "Partial Freeze"
- "desc": "The leviathan deals double damage to objects and structures."
"name": "Siege Monster"
- "desc": "The leviathan can enter a hostile creature's space and stop there. It\
\ can move through a space as narrow as 1 inch wide without squeezing."
"name": "Water Form"
"actions":
- "desc": "The leviathan makes one Slam attack and one Tail attack."
"name": "Multiattack"
- "desc": "*Melee Weapon Attack:* +14 to hit, reach 20 ft., one target. *Hit:* 21\
\ (2d12 + 8) bludgeoning damage plus 13 (2d12) acid damage."
"name": "Slam"
- "desc": "*Melee Weapon Attack:* +14 to hit, reach 20 ft., one target. *Hit:* 19\
\ (2d10 + 8) bludgeoning damage plus 10 (3d6) acid damage."
"name": "Tail"
- "desc": "The leviathan magically creates a wave of water that extends from a point\
\ it can see within 120 feet of itself. The wave is up to 250 feet long, up\
\ to 250 feet tall, and up to 50 feet wide. Each creature in the wave must make\
\ a DC 24 Strength saving throw. On a failed save, a creature takes 45 (7d12)\
\ bludgeoning damage and is knocked [prone](/Rules/Source/conditions.md#Prone).\
\ On a successful save, a creature takes half as much damage and isn't knocked\
\ [prone](/Rules/Source/conditions.md#Prone). The water spreads out across the\
\ ground in all directions, extinguishing unprotected flames in its area and\
\ within 250 feet of it, and then it vanishes."
"name": "Tidal Wave (Recharge 6)"
"legendary_description": "Legendary Action Uses: 3. Immediately after another creature's\
\ turn, the leviathan can expend a use to take one of the following actions. The\
\ leviathan regains all expended uses at the start of each of its turns."
"legendary_actions":
- "desc": "The leviathan moves up to its speed."
"name": "Move"
- "desc": "The leviathan makes one Slam attack."
"name": "Slam (Costs 2 Actions)"
"source":
- "MPMM"
"image": "/Rules/Source/bestiary/elemental/token/leviathan-mpmm.webp"
```
^statblock
## Environment
coastal, underwater