Leviathan

A primordial titan of the deep ocean, vast as an island and old as the sea itself, that surfaces perhaps once in a generation to feed. Where a kraken hunts, a leviathan simply arrives - swallowing ships, shoals, and the storms that herald it without distinction. It is not cruel, only immense and hungry, and the sea itself seems to bend around its passage.

Maw: piercing, melee 15 ft, +4 to hit, 4d8+9 piercing; a Large or smaller creature is swallowed on a failed Dex Quick save, taking 2d10 crushing each round inside, cooldown 3 rounds. Tail Sweep: bludgeoning, 30 ft, save Dex Quick, 3d10 bludgeoning and knocked prone on a failed save, cooldown 2 rounds. Tidal Surge: water, the leviathan heaves the sea into a wave, save Con Tough, 6d8 and swept 30 ft on a failed save, cooldown 3 rounds.

Leviathan Hide: resists nonmagical damage. Sea-Born: amphibious; storms gather in its wake. Unmovable Bulk: too vast to be held, knocked prone, or forcibly moved. Senses: Night Vision (120 ft), Vibration Sense (feels movement, water vibration, 90 ft).