Dungeon Magazine #152

The Plague Tree
The petrified Plague Tree was formed from the remains of a powerful arakhor, a treant of immense power. The corpse of the once noble guardian has been corrupted by the presence of numerous foul creatures that now inhabit the warrens carved into its interior. Most notable are the undead harpy raiders, wielding deadly poisoned arrows, that lair in its branches. But at the root of the plague tree lies an even more potent foe.