Goblin Siege Engine

Family: Goblin

Huge construct, unaligned

Armor Class 20 (natural armor)
Hit Points 178 (17d10 + 85)
Speed 30 ft.

22 (+6) 10 (+0) 20 (+5) 3 (–4) 11 (+0) 1 (–5)

Damage Resistances acid, fire
Damage Immunities poison, psychic; bludgeoning, piercing, and slashing from nonmagical attacks not made with adamantine weapons
Condition Immunities blinded, charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 120 ft., passive Perception 10
Languages understands the languages of its creator but can’t speak
Challenge 11 (7,200 XP)
Proficiency Bonus +4


  • Adaptable Locomotion. Moving through difficult terrain doesn’t cost the siege engine extra movement. In addition, it has advantage on ability checks and saving throws made to escape a grapple or end the restrained condition.
  • Ambulant Bunker. The fortified turret of a goblin siege engine offers its riders limited protection from outside attacks, serving as a mobile blockhouse. Riders wield ranged weapons, and warlords, spellcasters, or other persons of interest command battles from its advantageous heights. Cosmetic alterations and unique weapon replacements have been seen on individual siege engines.
  • Ready to Rumble. In addition to its six mechanical legs, a goblin siege engine can often be recognized by the radial acid jet beneath its turret, which allows it to handily dispatch enemies en masse. Other main armaments exist, however, from the relative banality of heavy ballistae to the splendor of arcane cannons.
  • Construct Nature. The siege engine doesn’t require air, food, drink, or sleep.
  • Defensive Mount. The siege engine can serve as a mount for one Large creature, up to four Medium creatures, or up to six Small or smaller creatures. While mounted, creatures riding in the siege engine’s turret gain half cover.
  • Immutable Form. The siege engine is immune to any spell or effect that would alter its form.
  • Magic Resistance. The siege engine has advantage on saving throws against spells and other magical effects.
  • Siege Monster. The siege engine deals double damage to objects and structures.


  • Multiattack. The siege engine makes three Slam attacks.
  • Slam. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 22 (3d10 + 6) bludgeoning damage.
  • Acid Jet (Recharge 5–6). The siege engine sprays a jet of acid in a 30-foot line that is 5 feet wide. Each creature in that line must make a DC 17 Dexterity saving throw, taking 40 (9d8) acid damage on a failed save, or half as much damage on a successful one.


Six segmented, insect-like limbs support a body resembling a squat, wooden tower surrounded by a steel parapet. Goblinoid riders within the armored turret take aim with their crossbows as the spidery metallic construct expertly navigates the crowded battlefield. The awful sound of the device’s mechanical stride is almost as disconcerting as the unhinged taunts from its riders.

Goblin siege engines were pioneered by derro engineers to aid their goblinoid allies. A siege engine faultlessly performs the commands of its creator or possessor and cannot do much more than defending itself if left without direction. The madcap versatility of a goblin siege engine makes it a valuable addition to any army or warband on the move, but these rare constructs can also protect derro and goblin settlements from more industrious aggressors.

Section 15: Copyright Notice

Tome of Beasts 3 © 2022 Open Design LLC; Authors: Eytan Bernstein, Celeste Conowitch, Benjamin L. Eastman, Robert Fairbanks, Scott Gable, Basheer Ghouse, Richard Green, Jeremy Hochhalter, Jeff Lee, Christopher Lockey, Sarah Madsen, Ben Mcfarland, Jonathan Miley, Kelly Pawlik, Sebastian Rombach, Chelsea Steverson, Brian Suskind, Mike Welham

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