Doctor Who: 10 Best NuWho Recurring Characters

Episodes: A Good Man Goes to War, The Snowmen, The Crimson Horror, The Name of the Doctor, Deep Breath

The leader of the Paternoster Gang and wife to Jenny Flint (also of the Paternoster Gang), Vastra is an incredibly smart detective, supposedly the inspiration for Sherlock Holmes within the Whoniverse. A Silurian friend of the Doctor's woken up by some human construction workers, she has gone on to help Scotland Yard with many cases, both in dealing with terrestrial criminals and extraterrestrial menaces they don't understand. 

She provides an interesting dynamic with both the Eleventh and Twelfth Doctors, able to match them in understanding alien cultures and worlds, even having an insight into the Doctor that other characters don't have. Just see where she delicately asks about the baby in A Good Man Goes to War or helps him through the regeneration crisis in Deep Breath.

But it's not just the dynamic with the Time Lord that sets her apart. She's an accomplished fighter like her wife, so she's a good character to work with the TARDIS team given the trouble that they tend to get themselves into. Furthermore, she manages to combine a sense of leadership (of the Paternoster Gang) with surprising levels of compassion for all living things. All of this makes Vastra really interesting, and it's always great to discover more about her.