Originally Posted by The Vorpal Tribble
All content is open to any and all BUT, please, let me know how their use in your games went. That's the deal.
I used the Biting Wind, the Morphine Fairies, and the Insomnus in one game to shake things up a little. The Insomnus turned out to be a bit much for my players--it was intended to be tough and they were several levels under its CR, but I ended up needing to nerf it into the ground to save them. That one was probably my fault, though.
The Morphine Fairies freaked my players out for a bit--they weren't sure what exactly they'd been injected with--but other than that not a lot to say, they were pretty standard obnoxious interference monsters. I also ran with the idea of fairies in lab coats for NPCs. Because it got me wondering about some interesting things...
The Biting Wind went down pretty fast to Power Word Pain once they knew it was a swarm and that they shouldn't be using single-target effects. They assumed it was just a single air elemental at first. Against a low-level party--which it would be, it's a low-CR monster--I think it's a bit much having a swarm that effectively disguises its swarm status. Still, it was a nice way to do something a little different.