10 Deadliest Doctor Who Villains

Of all the dangerous aliens introduced to the world on Doctor Who, few are as frightening as the Vashta Nerada. They are so small, they can't be seen directly, so they exist mostly in shadow. Also, they are voracious eaters, and they love to eat meat... any meat.

When the Doctor runs into them in "Silence in the Library," they are shown to be merciless predators capable of completely consuming a person's body (minus the skeleton) in less than a second. So while there isn't a lot of pain in that sort of death, the prospect of it occurring is frightening, to say the least.

The Vashta Nerada would stalk and attach themselves to a person, and once that happened, there wasn't much anyone could do to save them. What's even more frightening is that these minute carnivorous insects are sentient, and when they killed someone, they managed to take control of their body.

As a result, they would animate the dead to go after the living, and because they were wearing speech synthesizers on their suits, the Vashta Nerada would sound just like their victims as they slowly and methodically stalked the next person they set their sights on eating.