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Template Grafts | Universal Monster Rules

Thermophilic Ooze

Source Starfinder #21: Huskworld pg. 59

Thermophilic Ooze CR 3

XP 800
N Small ooze (fire)
Init +2; Senses blindsight (vibration) 30 ft., sightless; Perception +8


HP 41
EAC 14; KAC 16
Fort +6; Ref +0; Will -1
Immunities acid, fire, ooze immunities
Weaknesses cold


Speed 20 ft., climb 20 ft., swim 20 ft.
Melee pseudopod +11 (1d6+4 B; critical corrode 1d6)


STR +2; DEX +1; CON +4; INT —; WIS +0; CHA -3
Other Abilities compression, environmental reactivity, mindless, no breath


Environment any warm
Organization solitary, cluster (2–5), or colony (6–30)

Special Abilities

Environmental Reactivity (Ex) Though they aren’t harmed by acid or fire, thermophilic oozes react to such energies. Whenever a thermophilic ooze’s fire immunity prevents it from taking fire damage from an attack, it increases all of its speeds by 20 feet until the end of its next turn. Whenever a thermophilic ooze’s acid immunity prevents it from taking acid damage form an attack, it briefly becomes more dangerous; its pseudopod attack deals an additional 1d6 acid damage until the end of its next turn.


Evolving from colonies of bacteria native to undersea volcanic vents, thermophilic oozes are adapted to some of nature’s harshest and most inhospitable environments. On worlds with low amounts of tectonic movement and consistent volcanic activity, such bacteria can grow over the course of millennia, joining together into larger and larger forms. Eventually, these creatures gain enough cohesion to leave their fiery, corrosive homes, driven by a hunger for organic prey. With their amorphous bodies and immunity to fire and acid, thermophilic oozes have almost limitless access to places other creatures dare not tread, giving them zones of safety from which they can hunt. Thermophilic oozes can consume and gain sustenance from any organic matter, but many of them seem to prefer to chase down living creatures over immobile plants.

In addition to providing a safe haven, a thermophilic ooze’s warm and corrosive home environments are necessary to the creature’s long-term survival. When deprived of the acidity and heat of their homes for an extended period of time, the creatures need to eat more and more with each passing day. This makes them more aggressive when encountered outside of their native environments—such as those that hitch an unintended ride on an excavator or deep-sea submarine.

Thermophilic oozes are a particular nuisance near the planet Ilemchuuva’s underwater volcanic vents and mining sites. Local bolidas take great pleasure in exterminating them en masse, considering them to be a form of dangerous vermin. Bolida miners pass around stories of thermophilic ooze infestations left unchecked, leading to the loss of valuable equipment and, far more importantly, fellow workers. When outside of its preferred environment, a thermophilic ooze tends to take the shape of a flattened sphere roughly 3 feet across, though it can squeeze itself through quite small openings given enough time. A thermophilic ooze weighs approximately 300 pounds.