Tianna
Tianna (short for Eltiannachrisanik) was a Time Lord who worked in the Department of Administrative Records on Gallifrey.
While doing her work, Tianna noticed that someone had recently been through the Time Lord records, something that only an operator with High Council clearance should be able to do. She called the Eighth Doctor in to deal with the problem. He found that a Time Lord named Handrel had accessed the records to find information about ancient creatures such as vampires. Tianna called President Romana for backup so that Handrel's crimes involving a time scoop would be stopped. During the confrontation with Handrel, Tianna was bitten by the vampire, turning her into an immortal vampire. (PROSE: The Time Lord's Story)
Tianna was then removed from time by the Doctor to protect the Web of Time. (PROSE: Repercussions...)
