Perun
Mushroom
If you're interested in this subject, also check out the Runewild from Sneak Attack Press: The Runewild Campaign Setting - Sneak Attack Press | DriveThruRPG.com
I like it better than Margraeve (which is also excellent) but there are definitely ideas you could steal from both. Margraeve is more about "the forest is magic and turns you into a plant" and Runewild is more about "lots of fey here who will turn you into a swine."
Thanks! I'll look it up.