|Vehicles and/or Gadgets||None|
|Occupation|| Former Sontaran Commander
Madame Vastra's butler
|Residence||19th Century London|
Commander Strax was a Sontaran commander who was forced to serve as a nurse to restore the honor of his clone batch. He fought and died at the Battle of Demons Run to repay the Doctor, to whom he owed a debt for saving his life. Strax was later resurrected by Vastra and Jenny Flint and lived in Victorian London with them, acting as their butler. He still retains some warlike traits, such as a love for exotic weaponry (especially grenades) and an ever-present desire to leap into battle.
- He is voiced by Dan Starkey, the same actor who plays him on the TV show.