what you think. It works best for zombies, but with a little
forethought, it could probably apply to any undead (EDIT: except incorporeal.)
Plant-based Undead (someone else suggested I call them Verdant Undead)
Rather than being powered by negative energy, these undead are corpses
that have been overrun by a plant organism that animates their body.
-Type changes from Undead to Plant.
-HD changes from d12 to d8
-Attack bonus changes from 1/2 to 3/4 (like a cleric)
-Gains a Constitution score based on size. (I recommend Tiny 6, Small
10, Medium 12, Large 16, Huge 20, Gargantuan 24, Colossal 32)
-Since they are not truly undead, they lose all universal Undead
traits and gain all universal Plant traits (which are mostly the same
anyway. I.e. immune to critical hits, sleep, paralysis, etc.)
-Immune to turning and rebuking. Also not hurt, but rather healed by
cure spells. They are susceptible to damage from inflict spells.
-CR should increase a step (e.g. 1/3 to 1/2 or 3 to 4) to account for
the immunity to turning and the increased attack bonus.
In all other ways they should be just like the original undead.
Possible adventure hooks in a game:
-An evil druid develops an Animate Dead spell of her own and is
terrorizing the people of the town.
-Infestation of undead from a Far Realm that local clerics seem
powerless to defeat.
Potentially, you could apply the template to all undead and make it
make sense with a little modification. For example, a plant-based
vampire that sleeps by night in an earth-filled coffin and seeks out
blood by day. Might possibly be healed by sunlight spells, rather
than harmed. In that case, you may want to increase the CR a little more.