Skaak

Skaak was a Sontaran Commander in charge of the fleet involved during the time invasion of the Crimean War.

Biography
After Ritskaw led the attack on Earth during the events of the Flux, (TV: The Halloween Apocalypse), Skaak led the charge against the British Army in the Crimean War. He chose the Crimea both because he believed it to be the most appropriate starting point, and because he wanted to ride a horse. During the conflict, Skaak was informed by Svild that the Doctor was present in the time period and was requesting a parlay. Skaak agreed, but shot Svild dead at his request.

After the Thirteenth Doctor drained the supplies of the Sontarans, they were forced to retreat. As they were doing so, Skaak and his army were all killed when their ships were blown up by General Logan. (TV: War of the Sontarans)