There's a fox in my neighborhood.

I have never seen the fox. I have only heard it barking and howling. It sounds like a screaming baby. I only ever hear it when it's dark outside.

This sounds like it's straight out of a horror movie or something.

What would the plot device be?

Lame: Is it mostly harmless?
Cookie-cutter: Would it attack people in the neighborhood one by one? Possibly with rabies?
Overdone: Is it a zombie fox, signaling the beginning of the zombie apocalypse?
I Know What You Did Last Summer: Is it really a demon taking the shape of a fox to haunt the lives of a select few humans?

Seriously though, the way I only occasionally hear it is eerily reminiscent of one of those supernatural mindfuck horror movies.