Deep One — Ageless Hunter of the Drowned Cities
An ageless amphibious humanoid from the deep ocean, equally at home in abyssal trenches, drowned ruins and isolated coastal settlements.
A Deep One is a powerful aquatic humanoid with fishlike features, heavy claws and a body built to endure enormous changes in water pressure. They can breathe air and water, survive indefinitely without aging, and maintain hidden settlements in places where deep ocean canyons approach the coast.
At a Glance
Run It Tonight
Use the waterline as the tactical boundary. A Deep One can wade ashore, fight for a few rounds, then vanish beneath water where most adventurers cannot pursue effectively. The encounter becomes more interesting when the creature is defending a route, prisoner, relic or submerged entrance rather than simply attacking on sight.
Rules by Edition
Deep One
Medium Monstrosity, typically Chaotic Evil
AC 13; Initiative +1 (11)
HP 27 (5d8 + 5)
Speed 20 ft., Swim 40 ft.
17 (+3)
12 (+1)
14 (+2)
11 (+0)
13 (+1)
9 (−1)
Skills Perception +3, Stealth +3 (+5 underwater)
Resistances Cold
Senses Darkvision 60 ft.; Passive Perception 13
Languages Aklo, Common
CR 1 (200 XP); PB +2
Traits
Amphibious. The Deep One can breathe air and water.
Deep Dweller. The Deep One ignores damage and penalties caused solely by natural water pressure or rapid changes in depth.
Ageless. The Deep One does not suffer the effects of natural aging.
Underwater Stalker. The Deep One has Advantage on Dexterity (Stealth) checks while fully submerged.
Actions
Multiattack. The Deep One makes two Claw attacks.
Claw. Melee Attack Roll: +5, reach 5 ft. Hit: 6 (1d6 + 3) Slashing damage.
Bite. Melee Attack Roll: +5, reach 5 ft. Hit: 7 (1d8 + 3) Piercing damage.
Deep One
Medium monstrosity, chaotic evil
Armor Class 13 (natural armor)
Hit Points 27 (5d8 + 5)
Speed 20 ft., swim 40 ft.
17 (+3)
12 (+1)
14 (+2)
11 (+0)
13 (+1)
9 (−1)
Skills Perception +3, Stealth +3 (+5 underwater)
Damage Resistance cold
Senses darkvision 60 ft., passive Perception 13
Languages Aklo, Common
Challenge 1 (200 XP)
Traits
Amphibious. The Deep One can breathe air and water.
Deep Dweller. Natural water pressure does not harm it.
Ageless. It does not age naturally.
Actions
Multiattack. The Deep One makes two claw attacks.
Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage.
Deep One CR 1
XP 400
CE Medium monstrous humanoid (aquatic, deep one)
Init −1; Senses darkvision 60 ft., low-light vision; Perception +7
Defense
AC 12, touch 9, flat-footed 12 (−1 Dex, +3 natural)
hp 17 (2d10+6)
Fort +5, Ref +2, Will +5
Defensive Abilities deep dweller, immortal; Resist cold 5
Offense
Speed 20 ft., swim 40 ft.
Melee 2 claws +5 (1d4+3)
Statistics
Str 17, Dex 9, Con 16, Int 12, Wis 15, Cha 10
Base Atk +2; CMB +5; CMD 14
Feats Great Fortitude
Skills Intimidate +5, Knowledge (religion) +6, Perception +7, Stealth +4 (+8 underwater), Survival +7, Swim +16
Languages Aklo, Common
SQ amphibious, devoted, item use
Special Abilities
Deep Dweller (Ex). Deep Ones are immune to damage from water pressure and adjust instantly to changes in depth.
Immortal (Ex). They do not age and are immune to magical aging.
Item Use (Su). A Deep One can activate spell-trigger items as if it were a spellcaster of the appropriate class.
Ecology
Environment any water
Organization solitary, gang, cult or shoal
Treasure standard
Deep One
Medium Monstrous Humanoid (Aquatic)
Hit Dice 2d8+6 (15 hp)
Initiative −1
Speed 20 ft. (4 squares), swim 40 ft.
Armor Class 12 (−1 Dex, +3 natural), touch 9, flat-footed 12
Base Attack/Grapple +2/+5
Attack claw +5 melee (1d4+3)
Full Attack 2 claws +5 melee (1d4+3)
Special Qualities amphibious, darkvision 60 ft., deep dweller, ageless
Saves Fort +3, Ref +2, Will +5
Abilities Str 17, Dex 9, Con 16, Int 12, Wis 15, Cha 10
Skills Hide +4 (+8 underwater), Listen +7, Spot +7, Survival +7, Swim +16
Feats Great Fortitude
Environment aquatic
Organization solitary, gang or shoal
Challenge Rating 1
Treasure standard
Alignment usually chaotic evil
Compatibility Note
This 3.5e presentation converts the open Pathfinder chassis into 3.5e terminology rather than reproducing an official SRD Deep One.
Behaviour
Deep Ones think in terms of settlements, kin-groups and long spans of time. A human generation can pass while the same Deep One continues watching one harbour, reef or family line. That patience makes infiltration and bargains as important to them as raids.
They are capable tool users and spellcasters, and should not be run as mindless fish-men. A raiding party can scout tides, sabotage boats, use stolen wands and retreat before defenders understand what they were after.
Signs Before Initiative
- Wet footprints appear above the tide line after moonless nights.
- Fishing nets are cut cleanly rather than torn by animals.
- Old coastal carvings depict the same faces across several human generations.
- A drowned ruin contains fresh lamps, tools or offerings.
- Someone watches from offshore without needing to surface for breath.
- Cold seawater drips from a locked room far from the harbour.
If Violence Starts
Deep Ones fight to control access to water. They retreat through surf, flooded tunnels or cisterns, forcing land-bound enemies to choose between pursuit and safety. Several Deep Ones attack from different depths rather than bunching together on shore.
Counterplay
Block underwater escape routes before confronting a settlement. Light, ropes and marked lines help prevent the party becoming separated in murky water. Cold resistance means some common aquatic attack choices are less effective in PF1e and the modern compatibility versions.
Settlements and Coastal Influence
The largest Deep One communities lie where deep water comes unusually close to shore. That allows them to maintain contact with surface settlements without abandoning the safety of submerged canyons and ruins.
Some communities use fear and raiding; others rely on trade, inherited obligations or secret alliances. Surface families connected to them may act from genuine loyalty, intimidation or simple dependence on the protection and food the sea provides.
Using a Deep One in an Encounter
The ageless witness. A Deep One remembers a shipwreck that occurred two centuries ago and knows what was really aboard.
The drowned chapel. Lights appear every night inside a building that has been underwater for generations.
The harbour bargain. A fishing village prospers despite terrible weather, but nobody will explain who receives the first catch.
The trench road. A submerged canyon provides the fastest route to a lost ruin, but a Deep One settlement controls the passage.
Related Creatures
Compare the Deep One with the Skum and the Aboleth, or explore other aquatic creatures in the World Bestiary.
Rules Sources and Licensing
The Pathfinder 1e Deep One derives from Pathfinder Roleplaying Game Bestiary 5, © 2015 Paizo Inc., and provides the open mechanical anchor for this entry.
The 5.5e/2024, 5e/2014 and D&D 3.5e panels are compatibility adaptations created for this page and are not represented as official statistics for those editions.
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