Team TARDIS

Team TARDIS was a term used by the Thirteenth Doctor to refer to herself and her companions Graham, Ryan and Yaz. (TV: Arachnids in the UK)

The Doctor acted as leader at most times, but on occasion had to use Graham as a proxy in places where women were not considered equals. (PROSE: The Good Doctor, TV: The Witchfinders) Regardless, she was always respected by her friends, who reinforced her rules. (TV: Arachnids in the UK, Demons of the Punjab, The Witchfinders)

Team structure
The Doctor and Graham described their team as having a "very flat team structure", with each member bringing their own set of skills and areas of expertise. (TV: The Witchfinders)
 * The Doctor served as both the team leader (TV: Arachnids in the UK, The Witchfinders) and a teacher to her friends. (TV: Rosa, PROSE: The Secret in Vault 13)
 * Graham was the second oldest on the team, having years of wisdom, and often came to the aid and defense of others.
 * Ryan served as a pupil to the Doctor, having taken her rules to heart. (TV: Arachnids in the UK, The Witchfinders) He trusted, in the face of danger, that the group would always come out on top, (TV: The Tsuranga Conundrum) and often worked as an intermediary for the Doctor's thoughts and actions. (TV: The Witchfinders)
 * Yaz used her police officer skills in investigation and pacification to assist the Doctor in solving problems, de-escalating conflicts, and getting others to cooperate with them. People in need who encountered Team TARDIS were most likely to open up to Yaz, (TV: The Ghost Monument, The Witchfinders, It Takes You Away) again due to her training. (TV: It Takes You Away)