The Shakespeare Code
Mother Doomfinger was a Carrionite who, like the rest of her race, was banished to the Deep Darkness by the Eternals.
Doomfinger was allied with Bloodtide and Lilith, their goal being to release the Carrionites into the real world. Doomfinger killed Peter Streete when the Tenth Doctor, Martha Jones and Shakespeare visited him in Bedlam. She would have killed them as well, but the Doctor was able to name her as a Carrionite. By naming her, the Doctor banished her back to her kin. She was present at the Globe Theatre where Shakespeare’s new play was about to be performed. When Richard Burbage unwittingly said the lines to release the Carrionites, Doomfinger and her “family” were in victory, however they were imprisoned in a crystal ball, after Shakespeare defeated them using a word from the famous Harry Potter series by J. K. Rowling. (The Shakespeare Code)