Clockwork Nautiloid

Family: Clockwork

Huge construct (clockwork), unaligned

Armor Class 17 (natural armor)
Hit Points 161 (14d12+70)
Speed 10 ft., swim 40 ft.

26 (+8) 20 (+5) 20 (+5) 1 (–5) 11 (+0) 1 (–5)

Damage Immunities cold, poison, psychic
Damage Vulnerabilities lightning
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses blindsense 60 ft., darkvision 120 ft., passive Perception 10
Languages understands the languages of its creator but cannot speak
Challenge 14 (11,500 XP)


  • Deep Delver. The clockwork nautiloid is immune to the effects of water pressure.
  • Reflective Shell. The curved shell of a clockwork nautiloid resists certain magical effects. Spells which require an attack roll and line spells targeting a clockwork nautiloid are harmlessly deflected and have no effect.
  • Winding. A clockwork nautiloid can function for one month every time it is wound. A creature of at least Large size can use an action to wind the clockwork nautiloid, restoring it to one month of operating time; a creature of Medium size can wind it at half this speed, and Small or smaller creatures are generally unable to wind it.


  • Multiattack. The clockwork nautiloid makes one bite attack and four tentacle attacks.
  • Bite. Melee Weapon Attack: +11 to hit, 5 ft. reach, one target. Hit: 19 (2d10 + 8) piercing damage.
  • Tentacle. Melee Weapon Attack: +11 to hit, 15 ft. reach, one target. Hit: 12 (1d8 + 8) bludgeoning damage. Instead of dealing damage, the clockwork nautiloid can grapple the target (escape DC 18). A creature grappled by the clockwork nautiloid automatically takes damage from the tentacle attack at the beginning of each of the clockwork nautiloid’s turns. When the clockwork nautiloid has a creature grappled in this way, it has one less tentacle attack for its Multiattack for each creature it has grappled, up to a maximum of four creatures grappled.


Clockwork nautiloids are specialized, watertight clockwork creations designed to withstand the darkest, coldest ocean depths. A clockwork nautiloid resembles an oversized nautilus with a curved and magically strengthened shell. A clockwork nautiloid is 30 feet long and weighs 4 tons.

Its sharp, octopus-like beak is surrounded by dozens of tentacles that appear organic but contain rotors and pistons allowing for a strong, prehensile grip. Most of its tentacles end in a subtly serrated gripping pad, but two of them end in specialized sensory equipment shielded with durable crystal. These clusters provide the clockwork nautiloid with superior senses, allowing it to see even in the oppressive blackness of the deep ocean.

Single-Minded. Clockwork nautiloids pursue the directives of their creators with single-minded purpose, attacking any creature that interferes with their orders.

Although a clockwork nautiloid has many gripping tentacles, it can usually bring only four of these tentacles to bear in combat along with its snapping bite. Clockwork nautiloids are relentless combatants that pursue their opponents to any depth and even onto land, propelling themselves with their powerful tentacles.

Section 15: Copyright Notice

Mechanical Monsters (5E) © 2023, Legendary Games; Authors: Jason Nelson, Miguel Colon, Robert J. Grady, Nicholas Hite, Matt Kimmel, Michael Mifsud, James-Levi Cooke, Dan Dillon, Mike Myler, Ismael Alvarez, Jeff Lee, John Lynch.

This is not the complete section 15 entry - see the full license for this page