Deep One Elder

Family: Deep One

Gargantuan monstrosity (mythos), chaotic evil

Armor Class 19 (natural armor)
Hit Points 232 (15d20+70)
Speed 30 ft., swim 40 ft.

STR	DEX	CON	INT	WIS	CHA
25 (+7)	12 (+1)	21 (+5)	16 (+3)	18 (+4)	16 (+3)

Saving Throws Con +11, Wis +10, Cha +9
Skills Religion +8
Damage Resistances acid, cold, lightning; bludgeoning and slashing from nonmagical attacks
Senses passive Perception 14
Languages Common, Deep Speech
Challenge 17 (18,000 XP)

Special Traits

• Amphibious. The deep one can breathe air and water.
• Deep Dweller. Deep ones are immune to damage from water pressure; their bodies are capable of instantly adjusting to different water depths or even the surface with ease.
• Innate Spellcasting. An elder deep one�s spellcasting ability is Wisdom (spell save DC 18). The elder deep one can innately cast the following spells, requiring no material components:
• 3/day each: confusion (as an 8th-level spell), dream, freedom of movement, hold monster
• 1/day each: black tentacles, dominate monster, symbol
• Item Use. A deep one can use magic items as though it were a cleric, warlock, or wizard.
• Legendary Resistance (3/Day). If the elder deep one fails a saving throw, it can choose to succeed instead.
• Reflective Mind. Any time an elder deep one succeeds at a saving throw against a spell or magical ability that cannot affect creatures that are immune to being charmed or frightened or that inflicts psychic damage, the effect is reflected back on the source, affecting the original caster as if the elder deep one cast the spell or used that magical ability.

Actions

• Multiattack. The elder deep one can use its Awful Presence. It then makes three attacks: one with its bite and two with its claws.
• Bite. Melee Weapon Attack: +13 to hit, 5 ft. reach. Hit: 16 (2d8 + 7) piercing damage.
• Claw. Melee Weapon Attack: +13 to hit, 20 ft. reach. Hit: 14 (2d6 + 7) slashing damage. If the elder deep one scores a critical hit, it rolls damage dice three times, instead of twice, and the target must succeed on a DC 21 Constitution saving throw. On a failed saving throw, the target is stunned until the end of their next turn.
• Awful Presence. Each creature of the elder deep one’s choice that is within 120 feet of the elder deep one and aware of it must succeed on a DC 17 Wisdom saving throw or become frightened for 1 minute. A creature is incapacitated as long as it is frightened in this way. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the elder deep one�s Awful Presence for the next 24 hours.

Legendary Actions

An elder deep one 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 elder deep one regains spent legendary actions at the start of its turn.

• Claw Attack. The elder deep one makes a claw attack.
• Madness (Costs 2 Actions). All creatures other than deep ones within a 30-foot radius must makes a DC 18 Wisdom saving throw. On a failed saving throw, a creature is affected as the spell confusion until the end of its next turn. Creatures with total cover are not affected.
• Move. The elder deep one moves or swims up to half its speed without provoking opportunity attacks.

About

Deep ones are as at ease dwelling in the most remote of ocean trenches as they are in the shallows that hug secluded shorelines, although their favorite haunts combine the two.

The largest deep one cities are located at places not far off shore but nestled in vast submerged canyons unusually close to those coastlines. This proximity allows deep ones to pursue one of their favorite goals�commingling with and corrupting surface-dwelling humanoids. Deep ones do so not out of a biological need but as a way to spread their blasphemous religion above the ocean waves. The hybrid children of deep ones and humans form a race of their own. These offspring typically live near others of their kind, assuming positions of leadership in their small towns. A deep one’s gray-green hide glistens with moisture, and saliva dribbles from its fishlike maw.

Deep Devotees. Deep ones usually worship the alien entities known as the Outer Gods or the Great Old Ones, with Cthulhu the foremost among them. Deep one settlements that contain a deep one elder instead typically venerate that powerful deep one, who in turn serves one of the eldritch gods.

Underwater Wielders. Deep ones prefer to fight with their claws. If they do resort to manufactured weapons, they prefer piercing ones, as these function best underwater. They can also use wands and staves; deep ones who pursue the study of more powerful magic often learn to create magic items for their weaker kinfolk to wield.

Immortal. A deep one does not age. Barring death from violence, disease, or misadventure, a deep one can live forever. Deep ones are immune to effects that cause magical aging.

Deep Dweller. Deep ones are immune to damage from water pressure; their bodies are capable of instantly adjusting to different water depths or even the surface with ease.

Deep One Bishop. Deep one bishops incite religious fervor in their kinfolk and promote their chosen deities as the greatest among the Outer Gods.

Hybrid Horrors. Deep one hybrids are the spawn of humans and deep ones. They are most comfortable with others of their kind, and typically cluster in small, insular settlements where they can assume positions of authority. They keep any humans within their towns subservient and cowed, making sure those other residents know better than to act against local laws. Though deep ones are devoutly religious, they usually cloak their true beliefs under a facade of more conventional worship, believing that by doing so they can avoid suspicion from visitors and nearby societies.