Zu'nar
From Tardis Wiki, the free Doctor Who reference
The Zu'nar were a species who made a deal with the Council of Dead for thousands of human slaves. The Zu'nar were led to believe the Council controlled Earth. When the Eleventh Doctor defeated them, he planned to tell the Zu'nar the truth; he believed they would withdraw when they learned of the illegality. (PROSE: Attack of the Snowmen)