Tag: hazard

Hazard: Screamer Mushrooms

DM’s Toolbox: Hazard – Environmental Alarm System
Environment: Underground, damp caverns, abandoned tunnels, fungal groves
Type: Non-magical, organic hazard
Threat Level: Low (narrative complication or encounter trigger)

Screamer Mushroom Patch

Nuisance Hazard (Level 1-4)

One cluster of screamer mushrooms, small, bulbous mushrooms that seem to have a gossamer, balloon like cap, covers a 5-foot square. Screamer mushrooms have tremorsense to a range of 10 feet, and are sensitive to light or physical disturbance.  When exposed to light or movement, the mushrooms will release a burst of spores and deflate with a piercing shrieking wail that can be heard from 300 feet in open air, or 100 feet in obstructed environments through walls and doors.

To move safely through a Screamer Mushroom Patch, a creature must move no more than 5 feet per round, or succeed on a Dexterity (Stealth) check, with a DC of their desired speed. Any light above dim light falling on the mushrooms will trigger them.

A patch can release up to three bursts of spores before becoming dormant for 24 hours.

Screamer Mushroom Ecology

Not all dangers in the dungeon are deadly—some are simply loud. The Screamer Mushroom is a naturally occurring underground fungus that thrives in moist, dark environments and serves as a biological alarm system. These pale, waxy mushrooms are inedible and mildly toxic, but are prized by alchemists and hedge wizards for their magical and medicinal properties.

Behavior

Screamer mushrooms exist in loose clusters that respond to bright light or physical disturbance (such as movement, vibration, or touch). When disturbed:

  • The patch ejects a burst of spores that will cause the mushrooms to propagate, increasing in size and filling an adjacent square over the next week.
  • The sound can be heard from 300 feet in open air, or 100 feet in obstructed environments (such as caves with walls and doors).
  • Predatory creatures within range may be drawn to the sound, treating it as a signal of nearby prey.

Clearing the Patch

Screamer mushrooms can be destroyed easily with:

  • Fire
  • Thorough washing or flooding
  • Careful alchemical treatment

If disturbed during removal, however, the patch may still scream unless handled with care.

Spores left behind can re-root if not fully removed, especially in damp terrain. Removing or harvesting them in haste can leave enough residue for regrowth.

Alchemical and Magical Use

While toxic if ingested raw, Screamer spores can be refined into:

  • Minor healing elixirs (common potions of healing with a loud fizzing property)
  • Spell reagents for divination, enchantment, or necromancy spells
  • Noise-based traps or arcane alarms in arcane constructs or traps

Harvesting usable samples requires proficiency in Alchemist’s Supplies or Herbalism Kit and succeeds on an Intelligence (Nature) DC 13 check.  To harvest them quietly, a Dexterity (Stealth) DC 20 check is required.

DM Notes

  • Use Screamer Mushrooms to punctuate stealth-based dungeons, especially when players are trying to remain undetected.
  • Combine them with wandering monster mechanics—a triggered screamer may alert a nearby predator or trigger a lair reaction.
  • They make great environmental clues that a predator lairs nearby, or that someone has passed recently.

Notes

  • Updated for D&D Fifth Edition 2024 rules.