Large monstrosity, neutral evil

Armor Class 15 (natural armor)
Hit Points 133 (14d10+56)
Speed 10 ft., swim 40 ft.

17 (+3) 17 (+3) 18 (+4) 3 (-4) 12 (+2) 8 (-1)

Saving Throws Con +12, Int +10, Wis +9
Skills Athletics +6, Stealth +6
Senses darkvision 120 ft., passive Perception 12
Languages Abyssal, Aquan, Common
Challenge 5 (1,800 XP)

Special Traits

  • Water Dependency. The devilfish can only breathe underwater but can hold its breath out of water for 4 hours.


  • Multiattack. The devilfish makes one bite attack and two tentacle attacks.
  • Bite. Melee Weapon Attack: +6 to hit, 15 ft. reach, one target. Hit: 7 (1d8 + 3) piercing damage plus 14 (4d6) poison damage. If the target is a creature, it must succeed a DC 15 Constitution saving throw or become poisoned. A poisoned creature can attempt another saving throw at the end of each of its turns.
  • Tentacle. Melee Weapon Attack: +6 to hit, 15 ft. reach, one target. Hit: 7 (1d8 + 3) bludgeoning damage. Instead of dealing damage, the devilfish can grapple the target (escape DC 15).
  • Jet Away (1/Day). The devilfish can suddenly move 240 feet away in a straight line, provoking opportunity attacks.


  • Nautilus Defense. When attacked, a devilfish can harden its supple skin into a rigid nautiloid shell. This increases its AC to 17 but reduces its swim speed to 30 ft. and reduces the distance it can Jet Away to 120 feet. It can discard this shell at any time as a bonus action, but it cannot form a new shell until it has completed a long rest. The shell itself crumbles to sandy grit after 1 minute.


Although the devilfish superficially resembles a purplish cephalopod with a swarm of slashing spined arms, most often seven but some with as many as 13. These slashing arms are shaded a mottled blue, as are its octopoid eyes, though it sometimes retreats into a nautiloid shell. While it might appear to be simply a strange sort of octopus or squid, a devilfish is an altogether different creature with a heritage steeped in the lower planes. A devilfish is 10 feet long and weighs 500 pounds.

Fiendish Cunning. More than those of a mere animal, the devilfish’s intelligence and several of its abilities are gifts from a fiendish legacy-most sages believe that the original devilfish were once fiends from the Abyss, and that over the course of thousands of years they became true natives of the Material Plane’s oceans. Possessing a rudimentary intellect, a devilfish can understand and even speak a few words and phrases in various languages, although when it speaks, it has a tendency to mix languages together, making it somewhat difficult to understand for anyone who doesn’t speak all the languages known by the devilfish.

Rumors of far more intelligent devilfish dwelling in the deepest ocean trenches persist, although if these rumors are true, these deep-dwelling devilfish do not often come to the surface.

Section 15: Copyright Notice

Sea Monsters (5E) © 2021, Legendary Games; Authors Michael Ritter, Michael “solomani” Mifsud, Robert J. Grady, Mark Hart, Jeff Ibach, Alex Riggs, Scott D. Young, Jeff Lee, Matt Kimmel, and Jason Nelson.

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