Mushrooms in Hexen: Deathkings of the Dark Citadel's Hub 3: Chantry
Hexen continues the tradition of inert, hazardous things from Doom and Heretic with the poisonous mushroom.
These mushrooms are mottled brown with green spots. They are bursting with poisonous gas. Periodically, they visibly "twitch" and make a noise.
When struck, the gas is released in a cloud. This is the same gas that is released when the Cleric uses a fléchette.