Dan Starkey played Commander Skorr and Lieutenant Skree in The Sontaran Stratagem and The Poison Sky. He later played more Sontarans, Commander Jask in The End of Time, Commander Strax in A Good Man Goes to War and Jaka in the Big Finish audio drama The First Sontarans. He also played Cravnet in Robophobia and Plark in The Man Who Never Was -this was his first and final role in The Sarah Jane Adventures and the first TV character he has played who isn't a Sontaran.