Tarra (Doctor Who)

Tarra is a fictional character in the Doctor Who Expanded Universe novel The Ancestor Cell. She is not the leader, but a covert agent from Faction Paradox infiltrated (and presumably created) the Coven from that book. She is supposed to be a "rich kid" and the daughter of a powerful Gallifrey citizen.

During the time she is presented in the book, it becomes obvious that she's the most ruthless and prepared to do anything for the cause, as well as one of the few who actually knows The Coven deals in real voodoo and not just party tricks. She also acts as a honeypot around the boys of the Coven and Fitz, using her good looks to convince men, to gain their trust, as well as get necessary biodata from each of them. She camouflages her intents through (presumably faked) childish innocence, in so much that she has Fitz convinced Kellen was brainwashing her, which becomes evident is not the case.

While she is the gluing factor for The Coven, she also inadvertently creates tension between the male participants, in so far as some would be willing to kill their assumed competitors, or in Fitz's case, attempt to take her away, just to have her for themselves.