These are two of my favorite episodes from Doctor Who: Silence in the Library and Forest of the Dead. The Vashta Narada scared the crap out of me. Scariest. Things. EVER. In my opinion, they're scarier than the Weeping Angels. Yeah.
For non-Whovians, the Vashta Narada are NOT the skeleton spaceman. They're just inside the suit and the skeleton is what's left of the person they just ate. :D They're almost invisible. They live in the shadows and eat flesh. No big deal.
Also, you can't fight them. You have to run.
And count the shadows.
For emogit, though I dunno if you've seen this episode...If not, we're watching this together!
The Vashta Narada are not mine.