Jörmungandr

Gargantuan monstrosity, chaotic evil

Armor Class 17 (natural armor)
Hit Points 410 (20d20+200)
Speed 60 ft., climb 60 ft., swim 200 ft.

STR	DEX	CON	INT	WIS	CHA
27 (+8)	13 (+1)	30 (+10)	3 (–4)	20 (+5)	23 (+6)

Saving Throws Int +3
Skills Athletics +15
Damage Resistances cold, fire; bludgeoning, piercing, and slashing
Damage Immunities acid, poison; bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, poisoned, prone, stunned
Senses darkvision 300 ft., truesight 120 ft., passive Perception 15
Languages —
Challenge 23 (50,000 XP)

SPECIAL TRAITS

• Amphibious. Jörmungandr can breathe air and water.
• Damage Threshold. Jörmungandr does not take damage from an attack, spell, or other effect that deals 10 points or less of bludgeoning, piercing, or slashing damage (calculated after resistances).
• Freedom of Movement. Jörmungandr ignores difficult terrain, and magical effects can’t reduce its speed or cause it to be restrained. It can spend 5 feet of movement to escape from nonmagical restraints or being grappled.
• Legendary Resistance (3/Day). If Jörmungandr fails a saving throw, it can choose to succeed instead.
• Magic Resistance. Jörmungandr has advantage on saving throws made against spells and other magical effects.
• Magic Weapons. Jörmungandr’s weapon attacks are magical.
• Ponderous Tail. Whenever Jörmungandr makes a Colossal Tail attack, it does not strike until the end of its next turn. If the target of its attack has moved out of the area Jörmungandr misses the target but may hit other creatures or objects still in the area.
• Regeneration. Jörmungandr regains 10 hit points at the start of its turn. If Jörmungandr takes radiant damage, this trait doesn’t function at the start of its next turn. Jörmungandr dies only if it starts its turn with 0 hit points and doesn’t regenerate.

ACTIONS

• Multiattack. Jörmungandr attacks twice: twice with its black venom, or once with its bite, and once with either colossal tail or constrict.
• Bite. Melee Weapon Attack: +15 to hit, reach 30 ft., one target. Hit: 44 (6d10+11) piercing damage plus 27 (6d8) acid damage. In addition, at the end of its next turn the creature makes a DC 23 Constitution saving throw or it takes 27 (6d8) poison damage.
• Colossal Tail. Melee Weapon Attack: +15 to hit, reach 120 ft., multiple targets more than 20 feet away from Jörmungandr (120-foot cone centered on one target; roll separately for each creature and object in the area). Hit: 37 (4d12+11) bludgeoning damage and the target makes a DC 23 Strength saving throw or is knocked prone.
• Constrict. Melee Weapon Attack: +15 to hit, reach 20 ft., one creature. Hit: 38 (6d8+11) bludgeoning damage, and the target is grappled (escape DC 23). Until this grapple ends, the creature is restrained, and Jörmungandr can’t constrict another target.
• Black Venom. Ranged Weapon Attack: +8 to hit, range 50/100 ft., multiple targets (10-foot square; roll separately for each creature and object in the area). Hit: 27 (6d8) acid damage. In addition, at the end of its next turn the creature makes a DC 23 Constitution saving throw or it takes 27 (6d8) poison damage.

ABOUT

Jörmungandr is as if the ocean itself were given a beastly form and it is just as ruthlessly uncaring.

When a creature is so unlucky as to draw the world serpent’s attention the encounter that follows is almost always incredibly brief, the monster’s might quickly destroying the offender. In the rare instance that more than one blow is required Jörmungandr attacks whatever last meaningfully inflicted it harm, switching its targets with every strike it makes until all are obliterated.

There is no creature in existence longer than the world serpent, its body so impossibly long that it can wrap around a planet to bite its own tail—and it’s said that when it releases its grip that the end is nigh. Whether or not the myths about this massive wyrm are true it would be madness to deny the creature’s enormity, it’s tail stretching beyond the horizon. It is a thing of legend said to briefly surface only long enough to swallow a ship whole before disappearing back beneath the waves, sometimes undulating up into the air with its prey (whether vessel or giant sea creature) in its harbor-sized jaws.

Seamaster. At the start of any turn that Jörmungandr has pulled at least 200 feet or more of its body out of the water, its absence sends the sea tumbling. Creatures within 50 feet of the part of Jörmungandr’s body that is still submerged must make a DC 23 Strength saving throw or be knocked prone and pushed 50 feet away from it.

When Jörmungandr starts its turn with less than 200 feet of its body out of the water, creatures within 50 feet of it must make a DC 23 Strength (Athletics) check to move in the water. Any creature that has a swim speed makes this check with advantage.

Siege Monster. Jörmungandr deals double damage to objects and structures.

World Tremors (Recharge 6). Jörmungandr can use a bonus action to innately cast earthquake (DC 21) without the need for material components, somatic components, or concentration.