Sontaran flagship
From Tardis Wiki, the free Doctor Who reference
The Sontaran Flagship was a massive spacecraft that lead the Tenth Sontaran Battle Fleet into battle.
It was floating above Earth, where General Staal was spearheading the invasion. There was a teleport pod from the ship to Rattigan Academy.
The ship was destroyed by Luke Rattigan, when he activated a bomb. (DW: The Sontaran Stratagem/ The Poison Sky)
