|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 apparently died during the Battle of Demons Run to repay the Doctor, to whom he owed a debt for saving his life. It was later revealed that Strax was merely injured and was being a drama queen. He returned to Victorian London with Vastra and Jenny Flint and lived 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.
When The Doctor visits Victorian London, Strax can be found beside his damaged carriage. Strax requests the Doctor's aid in both rebuilding his carriage and defeating some Snowmen. Following the enemy's defeat and his carriage's reassembly, Strax rides off in search of more Snowmen to fight.
- He is voiced by Dan Starkey, the same actor who plays him on the TV show.