The Time of the Doctor
Starkey previously played Commander Skorr, one of the Sontarans, in the two-part story re-introducing the species, "The Sontaran Stratagem"/"The Poison Sky" (2008). He also portrayed another Sontaran character in "The End of Time" (2009–10) and in between appearances as Strax in "The Name of the Doctor" (2013) and "Deep Breath" (2014), he played two more Sontarans in "The Time of the Doctor" (2013).