Nosferatu

A "clichéd vampire archetype" was the most important character in a famous black-and-white, expressionist German horror film, (HOMEVID: Living Fiction) Nosferatu. (PROSE: Vampire Science) As a result, the vampire himself was sometimes informally referred to as Nosferatu. (PROSE: The Wonderful Doctor of Oz)

He appeared as a bald, "rat-like" vampire wearing a long, dark cloak. (PROSE: Vampire Science, The Slow Empire, HOMEVID: Living Fiction) Two scenes in the movie featured the vampire scaring a sailor and another man, respectively, by rising from his coffin. In another scene, he visited a living woman in her sleep, making his way to her bedroom in the form of a misshapen shadow. The ending saw the vampire being destroyed by sunlight.

In 2021, after a film reel of the original motion picture was infected with "pink goo" from Ecto-Space, an entity of Living Fiction gave itself shape by becoming a tangible, living version of the vampire. He killed several people in whose possession the "haunted" film reel had fallen, before it was requisitioned by the authorities and sent to PROBE. Giles and Maxie ultimately destroyed this real-life vampire by exposing the film reel to sunlight, copying the fictional character's demise in the film. (HOMEVID: Living Fiction)

Missy mentioned Nosferatu as one of the characters she had defeated in order to take over the Land of Fiction. (PROSE: The Wonderful Doctor of Oz)

Behind the scenes
Count Orlok, a copyright-skirting adaptation of Count Dracula in the real-life silent horror classic, has been referenced numerous times in the Doctor Who universe, and physically appeared (through reuse of public-domain footage of Nosferatu, where he was played by Max Schreck) in the P.R.O.B.E. short Living Fiction. However, he has never been explicitly named.