Doctor Who: EVERY NuWho Villain And Monster Ranked Worst To Best

Appears in: Silence in the Library/Forest of the Dead.

You know things are really serious when the Doctor says that the only way to overcome a man-eating swarm is to... run!

Steven Moffat, once again, takes one our most common fears - in this instance the dark - and utilises it to terrifying effect, à la how Ridley Scott played on the monster lurking in the shadows scenario in Alien. Moreover, there are similarities in what the Vashta Nerada and the Xenomorph are horrifyingly capable of - for the family-friendly version of Brett's gruesome demise we have the lovely but unloved Miss Evangelista ending up skeletonised by the piranhas of the air.

But it's the little things that make the Vasta Nerada one of the most memorably scary Doctor Who monsters: the lights blinking then going out, the sound effects of a foreboding swarm, the chicken leg instantaneously stripped to the bone, and the chilling thought that they're in any shadow.

So if you spot anyone looking warily at some dust in sunlight or chucking their packed lunch at a random patch of shadow, it's likely just a Whovian naturally wondering whether it's Vashta Nerada.