b'Marwolaeth \n'b'  Gargantuan   monstrosity ,  unaligned  \n'b'  Armor Class  19 (natural armor)  Hit Points  310 (20d20+100)  Speed  40 ft., swim 80 ft.\n'b' STATS STR: 27 (+8) DEX:  20 (+5)  CON:  20 (+5)  INT:  13 (+1)  WIS:  13 (+1)  CHA:  12 (+1)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'\n'b'  Saving Throws   Int +8,  Wis +8,  Cha +8  Skills   Athletics  +15,  Perception  +15,  Stealth  +12,  Survival  +15  Damage Vulnerabilities  lightning  Damage Resistances  acid, fire, thunder; bludgeoning, piercing, slashing  Damage Immunities  cold, poison  Condition Immunities   charmed ,  exhaustion ,  frightened ,  petrified ,  poisoned ,  stunned   Senses   darkvision  300 ft., passive  Perception  25  Languages  telepathy 200 ft.  Challenge  23 (50,000 XP) \n'b' SPECIAL TRAITS \n'b'\n'b'  Dark Sight . Magical  darkness  doesn\xe2\x80\x99t impede the marwolaeth\xe2\x80\x99s  darkvision . \n'b'  Freedom of Movement . The marwolaeth ignores  difficult terrain , and magical effects can\xe2\x80\x99t reduce its speed or cause it to be  restrained . It can spend 5 feet of movement to escape from nonmagical restraints or being  grappled . \n'b'  Hatchlings . A 30-foot radius cloud of parasitic offspring surrounds the marwolaeth. A creature that starts its turn in the area or first enters into the area on a turn must make a DC 20  Dexterity  saving throw. On a failure, it takes 14 (4d6) piercing damage and is  poisoned  until the beginning of its next turn. Humanoids that take 30 or more damage from Hatchlings become infected with marwolaeth spores which turn them into marwolaeths after 1d4 weeks without magical  healing  or invasive surgery. \n'b'  Legendary Resistance (3/Day) . If the marwolaeth fails a saving throw, it can choose to succeed instead. \n'b'  Magic Weapons . The marwolaeth weapon attacks are magical. \n'b'  Regeneration . The marwolaeth regains 30  hit points  at the start of its turn. If it takes lightning damage, this trait doesn\xe2\x80\x99t function at the start of the marwolaeth\xe2\x80\x99s next turn. The marwolaeth dies only if it starts its turn with  0 hit points  and doesn\xe2\x80\x99t  regenerate . \n'b'  Siege Monster . The marwolaeth deals double damage to objects and structures. \n'b'  Trample . The marwolaeth can use a bonus action to overrun creatures of Huge  size  or smaller, moving up to half its speed without provoking opportunity attacks. Creatures in the marwolaeth\xe2\x80\x99s path or sharing its space at the end of its movement make a DC 23  Dexterity  saving throw. On a failure, a creature takes 26 (4d8+8) bludgeoning damage and is knocked  prone . \n'b'\n'b' TACTICS \n'b' A marwolaeth begins combat by hitting the maximum number of targets with a sonic roar before using trample. Once within range of multiple targets, the marwolaeth grabs spellcasters and swallows them. The creature detects and engages the PCs when they are about a quarter of a mile away from the city and they near immediately after killing the creature. \n'b' ACTIONS \n'b'\n'b'  Multiattack . The marwolaeth uses its Frightful Presence. It then attacks three times: once with its bite and twice with its claws. \n'b'  Bite .  Melee Weapon Attack : +15 to hit, reach 15 ft., one target.  Hit : 24 (3d10+8) piercing damage. \n'b'  Claws .  Melee Weapon Attack : +15 to hit, reach 20 ft., one target.  Hit : 22 (4d6+8) slashing damage. If the target is a creature it is  grappled  (escape DC 23). \n'b'  Sonic Roar (Recharge 4-6) . The marwolaeth erupts with sound that travels in a 90-foot cone. Each creature in that area must make a DC 23  Dexterity  saving throw, taking 90 (20d8) thunder damage on a failed save, or half as much damage on a successful one. \n'b'  Swallow . The marwolaeth makes one bite  attack  against a Huge or smaller creature it is grappling. If the  attack  hits, that creature takes the bite\xe2\x80\x99s damage and is swallowed, and the grapple ends. While swallowed, the creature is  blinded  and  restrained , it has total  cover  against attacks and other effects outside the marwolaeth, and it takes 28 (8d6) acid damage at the start of each of the marwolaeth\xe2\x80\x99s turns. If the marwolaeth takes 40 damage or more on a single turn from a creature inside it, the marwolaeth must succeed on a DC 15  Constitution  saving throw at the end of that turn or regurgitate all swallowed creatures, which fall  prone  in a space within 10 feet of the marwolaeth. If the marwolaeth dies, a swallowed creature is no longer  restrained  by it and can escape from the corpse using 40 feet of movement, exiting  prone . \n'b'\n'b' ABOUT \n'b' These massive creatures are far less organic than their terrifying visage might lead one to believe, composed of a strange, otherworldy mix of cybernetics and fell genetics. \n'b' Marwolaeth all begin their existence as a humanoid of some kind (one unfortunate enough to have encountered one of the creatures) but each evolves to look slightly distinct from its kin. Regardless of the monster\xe2\x80\x99s appearance, these predators of the world\xe2\x80\x99s deepest waters are some of the deadliest entities on the planet, their very bodies designed to endlessly prowl the ocean floor at the behest of subtle directives encoded by unfathomable overlords millennia ago. \n'b' Jutting out of the underwater mountain you\xe2\x80\x99ve been steadily swimming up is a titanic outcropping of pipes, structures, and streets made entirely from metallic coral or crustacean plates. All of the mammoth settlement sits neatly under a field of energy similar to the anomaly far behind you and with some relief, you draw closer to dry land-or the closest thing you\xe2\x80\x99ll find to it under the waves-once more. \n'b' Rippling cords of hardened red muscles make up the enormous limbs of the monster that towers before you, easily the size of a country estate. Above its six glowing eyes is a blackened carapace laced with metallic engravings and circuitry that extends down along its shoulders and across its back.'