Cadborosaurus

Gargantuan Monstrosity, Neutral

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• Armor Class 17 (Natural Armor)
• Hit Points 310 (23d12 + 161)
• Speed 30 ft., swim 90 ft.

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STR	DEX	CON	INT	WIS	CHA
26 (+8)	14 (+2)	24 (+7)	8 (-1)	20 (+5)	16 (+3)

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• Saving Throws Str +14, Dex +8, Con +13, Wis +11
• Skills Perception +11, Stealth +8
• Damage Resistances Cold; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks
• Damage Immunities Poison
• Condition Immunities Frightened, Poisoned
• Senses Darkvision 120 ft., Tremorsense 60 ft., Passive Perception 21
• Languages Aquan, understands Common but cannot speak
• Challenge 19 (22,000 XP)
• Proficiency Bonus +6

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Legendary Resistance (3/Day). If the Cadborosaurus fails a saving throw, it can choose to succeed instead.

Magic Resistance. The Cadborosaurus has advantage on saving throws against spells and other magical effects.

Water Mastery. While in water, the Cadborosaurus has advantage on attack rolls and ability checks, and it can control currents around it, allowing it to move through the water without disturbing it. As a bonus action, it can create minor currents in a 30-foot radius, lightly pushing or pulling creatures at its discretion.

Innate Bioluminescence. The Cadborosaurus emits a faint, magical bioluminescent glow in a 30-foot radius, shedding dim light and imposing disadvantage on any Stealth checks made by creatures within this area.

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Actions

Multiattack. The Cadborosaurus makes three attacks: one with its Bite and two with its Tail Slap.

• Bite. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 26 (3d12 + 8) piercing damage. If the target is a creature, it must succeed on a DC 18 Constitution saving throw or become Paralyzed until the end of its next turn.
• Tail Slap. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 22 (3d10 + 8) bludgeoning damage. If the target is a creature, it must succeed on a DC 18 Strength saving throw or be Pushed 10 feet away and Knocked Prone.
• Arcane Maelstrom (Recharge 5–6). The Cadborosaurus summons a powerful vortex of magical energy in a 60-foot radius around itself. All creatures in the area must make a DC 18 Strength saving throw. On a failure, a creature takes 45 (10d8) force damage, is Pulled 20 feet toward the Cadborosaurus, and is Restrained until the end of its next turn. On a success, a creature takes half damage and isn’t restrained.

Hypnotic Glow. As a bonus action, the Cadborosaurus can intensify its bioluminescent glow. All creatures within a 30-foot radius must succeed on a DC 18 Wisdom saving throw or be Charmed by the Cadborosaurus for 1 minute. While charmed, creatures are incapacitated and entranced by its light. A charmed creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

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Legendary Actions

The Cadborosaurus 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 Cadborosaurus regains spent legendary actions at the start of its turn.

• Detect. The Cadborosaurus makes a Wisdom (Perception) check.
• Tail Sweep. The Cadborosaurus makes a Tail Slap attack.
• Whirlpool (Costs 2 Actions). The Cadborosaurus creates a swirling current in a 30-foot radius centered on itself. Each creature in that area must succeed on a DC 18 Strength saving throw or be Grappled (escape DC 18) by the whirlpool. The whirlpool lasts until the end of the Cadborosaurus’s next turn.

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Tactics

The Cadborosaurus uses its natural environment to its advantage, often starting combat with Arcane Maelstrom to pull foes close. It then uses Hypnotic Glow to incapacitate as many enemies as possible, allowing it to deal heavy damage with Bite and Tail Slap attacks. If surrounded, it will use its Whirlpool legendary action to maintain control over the battlefield. In water, it remains constantly on the move, using Water Mastery to flow seamlessly around attackers, evading attacks and disorienting foes. Its high intelligence drives it to focus on magical threats first, recognizing their potential to harm it despite its resistances.

Cadborosaurus, Sentinel of the Sunken Realms

Gargantuan Magical Beast (Aquatic)

Hit Dice: 28d10+168 (322 hp)

Initiative: +4

Speed: 20 ft., swim 80 ft.

Armor Class: 29 (-4 size, +23 natural), touch 6, flat-footed 29

Base Attack/Grapple: +28/+50

Attack: Bite +40 melee (4d8+12)

Full Attack: Bite +40 melee (4d8+12) and 2 Tail Slaps +35 melee (3d6+6)

Space/Reach: 20 ft./20 ft.

Special Attacks: Arcane Maelstrom, Hypnotic Glow, Improved Grab, Swallow Whole

Special Qualities: Darkvision 120 ft., Tremorsense 60 ft., Bioluminescence, Water Mastery, Damage Reduction 10/magic, Immune to cold and poison, Spell Resistance 30

Saves: Fort +23, Ref +14, Will +15

Abilities: Str 34, Dex 10, Con 22, Int 8, Wis 18, Cha 14

Skills: Hide +12, Listen +20, Spot +20, Swim +32

Feats: Improved Initiative, Multiattack, Improved Bull Rush, Power Attack, Cleave, Great Cleave, Combat Reflexes, Improved Toughness, Improved Natural Attack (bite), Improved Natural Armor

Environment: Any ocean depths

Organization: Solitary

Challenge Rating: 20

Treasure: None

Alignment: Neutral

Advancement: 29-35 HD (Gargantuan); 36-55 HD (Colossal)

Level Adjustment: —

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Special Abilities

Arcane Maelstrom (Su): Once every 1d4 rounds, the Cadborosaurus can unleash a powerful underwater vortex in a 60-foot radius. All creatures within the area must make a DC 30 Strength check or be pulled 20 feet toward the Cadborosaurus, taking 15d6 force damage. Those who fail are also entangled until they escape (DC 30). Creatures that succeed on the check take half damage and are not entangled. The save DC is Constitution-based.

Hypnotic Glow (Su): As a standard action, the Cadborosaurus can activate its bioluminescent patterns, causing all creatures within 30 feet to make a DC 22 Will save or be fascinated for 1d4 rounds. Fascinated creatures are entranced by the glowing patterns and take no actions unless attacked. A successful save renders a creature immune to the Hypnotic Glow for 24 hours. The save DC is Charisma-based.

Improved Grab (Ex): If the Cadborosaurus hits a creature of Large size or smaller with its bite attack, it can attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple, it establishes a hold and can attempt to swallow whole in the next round.

Swallow Whole (Ex): The Cadborosaurus can attempt to swallow a grabbed opponent of Large size or smaller by making a successful grapple check. Swallowed creatures take 3d8+12 bludgeoning damage and 2d8 acid damage per round. A swallowed creature can attempt to cut its way out with a light slashing or piercing weapon by dealing 30 points of damage to the creature’s stomach (AC 18). Once a creature exits, muscular action closes the hole; other swallowed creatures must cut their own way out.

Bioluminescence (Su): The Cadborosaurus sheds dim, magical light in a 30-foot radius, imposing a -5 penalty on Stealth checks for creatures within the area. Additionally, this light reveals invisible creatures, dispelling invisibility effects within this range.

Water Mastery (Ex): The Cadborosaurus has advantage on attack rolls, saves, and skill checks when in water. As a free action, it can create strong currents in a 30-foot radius around itself, lightly pushing or pulling creatures of its choice.

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Tactics

The Cadborosaurus uses Arcane Maelstrom to draw enemies close, then activates Hypnotic Glow to incapacitate as many foes as possible. It focuses on bite attacks and uses Improved Grab to restrain enemies, often swallowing weaker or smaller opponents whole. If surrounded, it will use its powerful tail slaps to sweep enemies away and Great Cleave to target multiple foes. With its high swim speed, it prefers hit-and-run tactics, circling its enemies and attacking from various angles to maintain control of the battlefield.

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Skills

The Cadborosaurus has a +10 racial bonus on Swim checks, allowing it to swim at full speed as a move action and perform accelerated swim maneuvers without penalty.