10 Doctor Who Villains Who Actually Won
6. The Vashta Nerada (Forest Of The Dead)
To give the Vashta Nerada credit, they only ended up in the planet-sized library after their forests were harvested to make books. To take that credit away from them, they're terrifying, flesh-eating nasties that hide in shadows and are completely relentless.
This is why the Doctor is forced to reason with them rather than actually defeat them. When confronted by the living darkness, the Doctor cuts them a deal - they give him one day to free the people trapped inside the library's data core, and then the library is theirs.
Of course, Ten succeeds in that plan. Well actually, River Song is the one who saves the day, but if we talk about her death scene then we'll just cry. All the people in the Library are saved, and then they leave, surrendering the complex to its new inhabitants.
The Vashta Nerada got exactly what they wanted, and then some. Not only did they find a new forest, but they also got some tasty snacks as a bonus!