Timbermoo
The extremely rare cosmic event, in which piles of timber, left to rot on a field combine to form a tree like zombie-cow, hellbent on... Well eating a tonne of grass really.
Random villager: "OMG! that cow's devouring my field"
Random villager's pirate friend: "Tht's no cow, tht be th' dreaded Timbermoo!"
Random villager's pirate friend: "Tht's no cow, tht be th' dreaded Timbermoo!"