First fan art post in two years, w00t. I just felt like putting one together again for Halloween this year. (Here's the one from 2009.)
No surprise for Azusa's costume.
This one might be harder to identify. Hint: Shizuru and Natsuki are on the broomstick.
Nanoha and Fate riding Raising Heart and Bardiche like broomsticks = my favorite pic in this post.
If you can't recognize these three, you are not a true card-carrying girls with guns fan.
Someone needs to make a Kyuubey jack o'lantern.
I didn't find anything yuri-relevant for Penguindrum, but... gah, penguins... cute!! Couldn't resist. XD