In order:-

The Sound Of Music
The hills are alive with the sound of Neuroi. Honestly, it kind of makes sense - the Von Trapp family, or at least their daughters, are about the right age for witch duty and generally Aiding The War Effort, and having Flandre and Meiling run into them might be amusing. I, er, also managed to get the name of the country wrong - they'd be from Ostmark, not Helvetia - which might have caused some confusion.

The Great Escape
This is a WW2-ish setting, but the Neuroi don't really do the whole "prisoners of war" stuff. So how do you have a POW camp? Easy: it's essentially a retirement home for witches who are in the process of losing their powers, to whom salvation has arrived in the form of the Von Hammer Method of Force Using. The staff, also old witches who've lost their powers, do their best to actively suppress the witches who've been losing them from learning about the method, culminating in a, er, great escape.

Chicken Run
You can't reference the greatest POW movie without referencing (in my opinion, at least) the greatest POW movie parody. It's a Great Escape-style film where almost the entire caste is composed of talking chickens made of plasticene; heroic protagonist Ginger is who I was referencing there. As you might already know, it was made by the same people who do Wallace And Gromit. Actually, Gromit might be a good choice for a familiar...

...

wait.

this was a dismissal, not a request for an explanation, wasn't it.

oh.

---
"She's old, she's lame, she's
barren too, // "She's not
worth feed or hay, // "But
I'll give her this," - he blew
smoke at me - // "She was
something in her day." --
Garnet Rogers, Small
Victory

FiMFiction.net: we might
accept blatant porn involving
the cast of My Little Pony but
as God is my witness we have
standards.