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Yellow Mould

Deadly fungus that covers walls, ceilings, and other surfaces

Type: Plant

Biome: Underdark

Stat Blocks

Old-School Essentials Classic Fantasy
Armor ClassNo hit roll required
Hit Dice2* (9hp)
Number Appearing1d8 (1d4)
Attacks1 Γ— spores (1d6 + choking)
THAC018 [+1]
Movement0' (0')
Saving ThrowsD12 W13 P14 B15 S16 (2)
Morale12
AlignmentNeutral
XP25
Treasure TypeNone

Monster statistics extracted from online SRD wiki, not the published hardcover edition.

Deadly fungus that covers walls, ceilings, and other surfaces.

Special Abilities

Area: Each 10 square feet (e.g. 2’ Γ— 5’) covered in yellow mould is treated as one “individual”. (A 10’ Γ— 10’ area would consist of 10 individual moulds.)
Immunity: Unharmed by all attacks but fire (a burning torch does 1d4 damage).
Spore cloud: 50% chance of attacking if touched (or damaged): releases a cloud of spores affecting all within a 10’ cube area.
Choking: Save versus death or die within 6 rounds.
Erosion: Wood or leather in contact with the mould will be eaten away.
Copyright 2017-2019 Gavin Norman. Open Game License v1.0a. License
OSRIC

Monster statistics extracted from online SRD wiki, not the published hardcover edition.

When touched, yellow mould releases spores in a 10-ft cubed choking cloud. Any creature within this area will die unless it successfully saves vs poison; a character who fails his or her save will require a cure disease and resurrection to be made whole again. If a surface covered in yellow mould is handled roughly, there is a 50% chance spores will be released in such a cloud.

Yellow mould is susceptible only to fire and fire attacks. A continual light spell will force the mould to go dormant for 2d6 turns until it covers the light source.