Shrieker (Basic Lore)

Shrieker (CR 1)
Neutral - Small - Plant
Shriekers are nasty fungi who have taken the whole 'live on decaying matter' to the logical extreme, by killing everything that moves anywhere close to them. As plants they obviously have no mind at all, but intelligent monsters will often cultivate shriekers as 'living burglar alarms'. This strategy works well, as long as you are always careful to stay well away from their planter once it's established.