Sontaran scout ship
From Tardis Wiki, the free Doctor Who reference
Sontaran Scout ships were large, spherical vehicles created by the Sontarans. As the name suggests, they may scout ahead before a fleet to investigate or infiltrate the enemy.
Several scout ships may be seen orbiting the main Sontaran Flagship during the Sontaran invasion of Earth. (DW: The Sontaran Stratagem/ The Poison Sky)
