I need help statting up The Grieving Tree

[blargney the second]

To my surprise, the players in my 3.5 Eberron campaign just accidentally activated (and attracted the attention of) a Dhakaani grieving tree. It's the same kind of artifact found in Don Bassingthwaite's eponymous novel.

...but I have no stats for it. Help, please?
-blarg

 

[ValhallaGH]

Choose a CR. Find a demon / devil of the same CR. Use those stats but describe it as appropriate for a Grieving Tree. Minor mechanical changes will also be required (creature type; not core things like BAB or ability scores).
For a scary end-boss type, I've occasionally used a Dragon, sans flight.

I've used this a few score times in a half-dozen campaigns to great success, when I needed a monster and had no real starting point for the stats.

Best of luck.