Alaya

Alaya was a female Silurian warrior from a vast underground city that was disturbed by a Welsh mining facility in the year 2020. She came to the surface and took people as hostages. (DW: The Hungry Earth)

History
Alaya came to the surface and took Elliot under the ground, Amy Pond and Mo under ground to be kept as hostage. The Doctor sprayed her with a Carbon Dioxide fire extinguisher and Rory bundled her into the back of a Meals on Wheels van. She was then locked and chained up in the crypt of the church where she rejected the Doctor's attempts at making peace between the Silurians and Humans. When the Doctor and Nasreen Chaudhry left for the Silurian settlement, Alaya said to the remaining group that one of them would kill her and she knew which one, but did not reveal who. (DW: The Hungry Earth)