WYSIWYG Daemonic Possession

I'm looking for ideas on representing the Daemonic Possession on an Undecided Chaos vehicle for WYSIWYG purposes. My GoogleFU is useless.

Thoughts?

One of my friends back home used to use green stuff to make demon faces on his tanks. Its really easy for preds and rhinos, because the front can easily be turned in a face, a bit harder for Land Raiders.

I did tentacles all over my tanks.

Works for nurgle, but add a few spikes a diff color scheme and i think it will work for any of the chaos gods.

I like the face idea there. I'm sure I could manage that.

I do have some Skaven tails lying around which pass off as tentacles, but that feels too Nurgle as you suggested Matt.

you could use the panels that came with the old chaos rhinos (they had faces on them).

recede them into the model then green stuff it to make it look flush.