In the other thread, I detailed the Parliament of the Emerald Frond, a court of Plant fae, wood elementals, and a few other odds and ends.
The PCs encountered them once when they were en route to destroy the Ghoul King, a ghoul who led a group of cannibalistic humanoids. A beautiful woman with flowers growing from her skin (and butterflies fluttering all around) stopped them at a table of amber, offered them tree stumps and long, leafy couches to sit on, and some nectar to drink. She also had a jaguar which spoke in her voice (and she just moved her mouth).
This was Sanguine Orchid, a speaker for the Parliament. The Ghoul King was their ally, and they were duty-bound to protect him. However, the Parliament wanted to reach out to the new kids on the block (the colony, that the PCs were representing), and they engaged a skill challenge of jockeying for approval/respect from Sanguine Orchid. The Parliament was annoyed the PCs had been logging in the jungle, cutting down TREES.
They succeeded. (In the middle of this, the bard faked drinking the nectar wine, the paladin drank it unfortunately). She finally said, "Well, we can deal with you just fine. However, just to remind you, the Ghoul King is our ally. So, we are duty bound to protect him. Nothing personal." And then the couches turned into thorny horrors, and the jaguar pounced.
The battle raged on. Near the end, Sanguine threw a vial of the nectar onto the amber table, then she fled. The amber table began to disolve, freeing a giant venus fly trap from inside. (But at that point, the session ended, and we were down a man, so I just hand-waved it.)
It was amusing, because one of the PCs was like, "These are plants and faeries. Why are they allying with UNDEAD? That's against the Natural Order!" Well, little did the PC know that the Ghoul King was tasked with keeping Hyena in check. Hyena, in my campaign, are pre-gnolls; a hyena eats a mortal's soul, it becomes a gnoll, and starts venerating demons. Demons corrupt anything they touch (particularly nature, particularly elementals), so they freak the heck out of the Parliament.
In a Keep on the Shadowfell game, my players ran across a pair of gnomes hunting a rogue gnome named Asgrid who had "not paid proper tribute to their majesty"; they were wearing Official Bounty Hunting outfit (which looks like a British Fox Hunting ensemble), acting as official vassals of a local faerie noble. The PCs, when they kicked Asgrid's ass, handed the gnome over to the other two.
When a player wanted to play Fey Warlock in the group (another gnome, amusingly), I had him draw up his Patron, the one who is giving him his power. He decided on a powerful entity of Delirium and Mad Dreams; a fearie locked away somewhere deep in the Feywild. Every time he kills a foe of his Pact Boon, his mistress sips at their memories and dreams.
She's sending him to the Keep, to unlock one of her Vassals, who is bound in the caves beneath the Keep.
In an earlier campaign, I had some pixies pretend to be the spirit of a river, convincing everyone that the river was mad, and so that anyone who wanted to cross the river had to do outrageous things in order to be allowed to cross.