Cutting it really close today (here is still half an hour of the 19th left)... I need to write something else tomorrow (and a favorite fey is easy, so that won't be a problem).
I like all plants, the HackMaster monster varieties idea isn't working that well (just didn't have the time, it was a busy week), so I'll go with the favorite elemental. It's the:
They remind me of the troll in the Scandinavian folklore, and that's all I need to know. Behold: