Starfinder: Burrowing Horror

Chris Van Deelen

Burrowing Horror Combatant CR 8 XP 4,800

Neutral large vermin

Init +4; Senses: Blindsight (Bones) 200 ft., Blindsight (vibration) 240 ft., Darkvision 60 ft. ; Perception +16


Defense                                                             HP 125

EAC: 20; KAC: 25

Fort: +12; Ref: +10; Will: +7

Defensive Abilities: Absorb bones, DR 8 / blunt; Immunities: Acid, disease, poison



Speed: 30 ft.

Melee: Bite +19 (single bite), +15 (multiple bites) (1d10+12 P) +12 claw (1d6+12 S)

Space: 10 ft., Reach: 10 ft.

Offensive Abilities: Blood to acid



Str +4; Dex +4; Con +4; Int -; Wis +0; Cha +0

Skills: Athletics +16, perception +16, stealth +21

Other Abilities: Absorb bones, poison water

Languages: None



Environment: Any temperate plains

Organization: Solitary, small group (1d3+1)


Special Abilities

Absorb Bones (Su): Any creature killed by this creature will be absorbed into the creature’s body. This requires a single full round action, and  It will automatically gain a number of hit points equal to half of the victim’s original hit point total. Any creature absorbed in such a manner is permanently dead. It can use this ability at will.

Blood to Acid (Ex): When the creature bites, it injects a chemical which causes the water molecules to become altered, binding with the water molecules in the blood to become a powerful acid. Anyone struck by this ability (through a bite attack) is allowed a Fort Save DC 16. If the save fails, the toxin will inflict 2d8+8 points of damage per round for 1d4 rounds, as the very blood of the victim begins to eat its way from the inside out. If the victim’s hit points are reduced to below zero, the creature’s entire organic matter will have melted away, leaving behind a skeleton, ripe for the mutant monster to use.

Poison water (Ex): By spending at least 3 rounds in any form of water, it will take on the toxic properties of acid. This will not be readily noticeable at first – someone drinking or entering a contaminated water source will not notice anything is amiss for 1d4 rounds. After that, the acid will begin to take effect. Moving through a contaminated source will inflict 2d8+8 points of damage per round, as long as the creature remains inside the medium. As soon as it leaves, the damage will stop. Anyone drinking the liquid will suffer the same damage as listed in the blood to acid ability, for the same duration as if they were injected.


No one knows for sure where this creature originated, as it has been discovered on numerous worlds across the galaxy. It is speculated that these creatures were originally from another plane of existence, and found gateways or portals into the prime plane, but this has never been proven.

This is a creature which lives deep in the soil of deserts and flat-lands, which uses the bones of the dead to form a framework, allowing it to move and burrow far more quickly than it otherwise could. The creatures resemble worms, typically being about 3-5 inches in length, although they are now obsidian-black in coloration. These creatures secrete a slime which acts like a powerful adhesive, allowing them to meld together to form sinews and musculature, which they use to wrap around the bones and skeletal remains of dead beasts and beings, allowing them greater mobility and access to natural weapons.

When they find a mass of bones, the creature forms a network by bonding with other members of its own kind and they surrounding the structure of the skeleton, often incorporating the remains of other skeletons to make up for any missing limbs or the critical structures they require to animate the remains.

Most of the time the skeletal remains they use are quadrupedal or bipedal in shape, almost always consisting of two legs, two arms, a spinal column and 1d3 skulls, all from various creatures, to use as weapons. More often than not, the creatures will have a humanoid skull and an animal skull. When encountered, the creature will have 1d3+1 claw attacks, thanks to the various bones it uses for a body.

The monsters also have a deadly attack, a toxic secretion they use on the claws and teeth of the skeleton. When a subject is bitten or clawed, they must make a saving throw versus poison or their blood will become acidic for a short period of time. This monster also uses the same secretion to poison water supplies. Water so contaminated is no longer potable, and must be disposed of or it can be used as a weapon in its own right.

When these creatures engage in combat, they attack with each head, biting and trying to inject the toxin. They can also strike with claw attacks per round. Due to their physical nature, the creatures have a natural damage reduction against piercing and slashing weapon attacks (which includes bullets), but take full damage from bashing or energy-based attacks.  After they have sustained damage, if there are any bones around, they can incorporate the skeletal structure of other creatures into their own bodies, repairing any damage.

These monsters survive by feeding upon the sloughed-off melted flesh, muscle and organic compounds of their victims, while using the bones to create their bodies. Once a creature has consumed enough food, it will split into smaller bodies. These will then eventually leave their parent and seek out territory of their own.

Hunting is accomplished by borrowing into the ground and waiting for prey, or simply using their unique sense to track down corpses or deposits of bone to use to repair or create a new body. This sense has a range of 200 feet. When they burrow they are slower, but they can sense the presence of vibrations on the surface up to 240 feet, and they will travel towards the source, potentially gaining surprise.  

It should also be noted these creatures will never retreat, they will always stay and fight until they or their prey has been vanquished.

Starfinder Creature Index

Chris Van Deelen is the creator and contributor to over half of the Wisdom from the Wastelands series, contributor to the Swords of Kos: Hekaton anthology. He also wrote Creatures of the Tropical Wastelands, and 100 Oddities found in a Car. As prolific as he is, Chris Van Deelen continues to write and produce material which will be in publication soon. Not only is he a prolific content creator, he also has a wide selection of fiction and stories! If you like his work, please follow his personal author page on Facebook and on Twitter to keep up with his latest news and game content.