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From Pathfinder Society Special #3-98: Expedition Into Pallid Peril, which isn't enabled.

Mutated Brown Mold

HAZARD 6
Stealth +18 (expert)
Description This unassuming fungus leeches heat out of the air.

Disable DC 25 Survival (trained) to safely remove the mold

AC 24; Fort +17, Ref +11
HP 54 (BT 27); Immunities critical hits, fire, precision; Weaknesses cold 15

Emit Cold (aura, cold)

10 feet. Enhanced brown mold deals 2d8+7 cold damage to nearby creatures.

Leech Warmth
Trigger Fire comes within 5 feet of the brown mold.

Effect The brown mold expands into every square adjacent to its space. As it grows, it pulls more heat from its surroundings, dealing 4d8+14 cold damage (DC 24 basic Fortitude save) to creatures within 15 feet after it expands.
Reset After expanding, the brown mold can't grow again for 1 day.
Pathfinder Society Special #3-98: Expedition Into Pallid PerilOGL