Clockwork Mantis

Family: Clockwork

Large construct, unaligned

Armor Class 15 (natural armor)
Hit Points 68 (8d10 + 24)
Speed 40 ft.

13 (+1) 19 (+4) 16 (+3) 3 (-4) 15 (+2) 1 (-5)

Skills Perception +5, Stealth +7
Damage Immunities poison, psychic; bludgeoning, piercing, and slashing from nonmagical attacks not made with adamantine weapons
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 60 ft., passive Perception 15
Languages understands Common but can’t speak
Challenge 6 (2,300 XP)

Special Traits

  • Hobbling Strike. When the clockwork mantis makes a successful opportunity attack, the target’s speed is reduced to 0 until the start of its next turn.
  • Immutable Form. The clockwork mantis is immune to any spell or effect that would alter its form.
  • Magic Resistance. The clockwork mantis has advantage on saving throws against spells and other magical effects.
  • Standing Leap. The clockwork mantis’s long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.


  • Multiattack. The clockwork mantis makes two serrated blade attacks. If both attacks hit the same target, the mantis can make a bite attack against another target within range as a bonus action.
  • Serrated Blade. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.
  • Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) piercing damage.
  • Invisibility. The clockwork mantis turns invisible until it attacks or until its concentration ends (as if concentrating on a spell). Any equipment the mantis wears or carries is invisible with it.


This large clockwork mantis is surprisingly nimble and fast, capable of taking down foes with a lethal flurry of serrated claws and bites.

These marvelous mechanical constructs were originally designed by the gnomish master engineer. Dreading that they were too powerful to be released into the world and fall into the wrong hands, he secreted them away. Whether they were released by a destruction-bent agent of chaos, or they somehow effected their own freedom, they are now a threat to any who cross their paths.

Uncontrollable and Invisible. In the past, the engineer was able to control his machines, which were built to be invisible agents and protectors. But the creations outlived their creator. If the secret to controlling the creatures exists anywhere, it is within the heavily secured vaults the engineer left behind.

Wanted by Gnomes. The existence of these wandering clockwork monsters creates a bad reputation for peaceful gnomish engineers. A few groups of gnomes specialize in tracking and destroying these clockwork creations. They claim to do it out of virtue, but rumors abound that they do it for rare parts or the possibility of tracking down the engineer’s vault.

Construct Nature. The clockwork mantis doesn’t require air, food, drink or sleep.

Section 15: Copyright Notice

Tome of Beasts 2. © 2020 Open Design LLC; Authors Wolfgang Baur, Celeste Conowitch, Darrin Drader, James Introcaso, Philip Larwood, Jeff Lee, Kelly Pawlik, Brian Suskind, Mike Welham.