Ancient Sea Serpent

Traits

Amphibious

The sea serpent can breathe air and water.

Legendary Resistance (2/Day)

If the sea serpent fails a saving throw, it can choose to succeed instead.

Siege Monster

The sea serpent deals double damage to objects and structures.

Actions

Multiattack

The sea serpent makes one Bite attack and one Constrict or Tail attack.

Bite

Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 20 (2d12 + 7) piercing damage plus 6 (1d12) cold damage.

Constrict

Melee Weapon Attack: +12 to hit, reach 20 ft., one creature. Hit: 29 (4d10 + 7) bludgeoning damage, and the target is grappled (escape DC 20). Until this grapple ends, the target is restrained, and the sea serpent can't constrict another target.

Tail

Melee Weapon Attack: +12 to hit, reach 20 ft., one target. Hit: 13 (1d12 + 7) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be pushed up to 30 feet away from the sea serpent and knocked prone.

Rime Breath (Recharge 5–6)

The sea serpent exhales a 60-foot cone of cold. Each creature in that area must make a DC 18 Constitution saving throw, taking 49 (9d10) cold damage on a failed save, or half as much damage on a successful one.

Legendary action uses: 3. The creature can use one option at the end of another creature’s turn and regains spent uses at the start of its turn.

Legendary actions

Tail

The sea serpent makes one Tail attack.

Bite (Costs 2 Actions)

The sea serpent makes one Bite attack