The Sontaran Flagship was the massive spacecraft that lead the Sontaran Empire's Tenth Battle Fleet.
The ship had the appearance of a ball with eight curved claws. For battle, the top and bottom claws could withdraw and lock together to reveal a cannon that could devestate a planet's surface. Along the center of the ball were docking ports for dozens of Sontaran Scout Ships.
Commanded by General Staal, the Flagship orbited above Earth as the spearhead for a Sontaran invasion to turn Earth into a cloning world. The ship was connected to the planet via teleport pods between the ship, the ATMOS Factory and the Rattigan Academy.
The ship was eventually destroyed by Luke Rattigan, when he activated his Atmospheric Convertor on the bridge. (DW: The Sontaran Stratagem/ The Poison Sky)