Source: Monster Manual (2024) p. 125. Available in the SRD and the Free Rules (2024)
If exposed to light or otherwise disturbed, mushroom-like shriekers emit a high-pitched noise that gives them their name. This wailing might alert other creatures or attract predators.
Fungi
Deadly Spores and Predatory Polyps
Habitat. Underdark
Treasure. None
The dank, sunless Underdark is a fertile breeding ground for weird and dangerous fungi.