Mordenkainen's Tome of Foes

ELDER ELEMENTALS

On their native planes, elementa ls sweep across the

weird and tempestuous landscape. Some possess

greater power, gained by feeding on their lesser kin and

adding the essence of creatures they have devoure d to

their own until they become something extraor dinary.

When summoned, thes e elder elementa ls manifest as

beings of apocalyptic ca pability, entities whose me re ex-

istence promises destruction.

Deadly When Summoned. The methods for sum-

moning elder elementals remain h idden in forbidden

tome s or inscribed on the walls of lost temples raised to

honor the Elder Elemental Eye. Only casters of s uper-

lative skill have even the faintest chance of calling forth

one of these monsters, and the spellcaster is often de-

stroyed by the effort. Thus, only the most unhinged and

nihilistic members of Elemental Evil cults attempt such

a summoning, in the hope of hastening the world toward '

some cataclysmic end.

Elemental Nature. An elder elementa l doesn' t require

air, food, drink, or sleep.

LEVIATHAN

Gargantuan elemental, neutral

Armor Class 17

Hit Points 328 (16d20 + 160)

Speed 40 ft., swim 120 ft.

STR

30 (+10)

DEX

24 (+7)

CON

30 (+10)

Saving Throws Wis +10, Cha +9

INT

2 (-4)

WIS

18 (+4)

CHA

17 {+3)

Damage Resistances bludgeoning, piercing, and slashing from

nonmagical attacks

Damage Immunities acid, poison

Condition Immunities exhaustion, grappled, paralyzed,

petrified, poisoned, prone, restrained, stunned

Senses darkvision 60 ft., passive Perception 14

Languages - • , .

Challenge 20 (25, 000 XP) • •

Legendary Resistance (3/Day). If the leviathan fails a saving

throw, it can choose to succeed instead.

Partial Freeze. 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.

Siege Monster. The leviathan deals double damage to objects

and structures (included in Tidal Wave).

Water Form. 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.

ACTIONS

Multiattack. The leviathan makes two attacks: one with its

s lam and one with its tail.

Slam. Melee Weapon Attack: +16 to hit, reach 20 ft., one tar-

get. Hit: 15 (ldlO + 10) bludgeoning damage plus 5 (ldlO)

acid damage.

CHAPTER 6 I .BESTIARY

Tail. Melee Weapon Attack: + 16 to hit, reach 20 ft., one tar-

get. Hit: 16 (ld12 + 10) bludgeoning damage plus 6 (ld12)

acid damage.

Tidal Wave (Recharge 6). While submerged, the leviathan mag-

ically creates a wall of water centered on itself. The wall is up

250 feet long, up to 250 feet high, and up to 50 feet thick.

When the wall appears, all other creatures within its area

must each make a DC 24 Strength saving throw. A creature

takes 33 (6dl0) bludgeoning damage on failed save, or half as

much damage on a successful one.

At the start of each of the leviathan's turns after the wall

appears, the wall, a long with any other creatures in it, moves

50 feet away from th e leviathan. Any Huge or smaller creature

inside the wall or whose space the wall enters when it moves

must succeed on a DC 24 Strength saving throw or take 27

(5d10) bludgeoning damage. A creature takes this damage

no more than once on a turn. At the end of each turn the wall

moves, the wall's height is reduced by 50 feet, and the damage

creatures take from the wall on subsequent rounds is reduced

by ldlO. When the wall reaches 0 feet in height, the effect ends.

A creature caught in the wall can move by swimming. Be-

cause of the force of the wave, though, the creature must make

a successful DC 24 Strength (Athletics) check to swim at all

during that turn.

LEGENDARY ACTIONS

The leviathan 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. The le-

viathan regains spent legendary actions at the start of its turn.

Slam (Costs 2 Actions). The leviathan makes one slam attack.

Move. The leviathan moves up to its speed.

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