With Bram Stoker's "Dracula" in the public domain by this time, Herzog was able to use most of the characters from that novel (though, oddly enough, he switched the identities of Lucy and friend Mina) while retaining the story of filmmaker F.W. Murnau's original.
The original "Nosferatu," based on "Dracula" by the brilliant Bram Stoker, was reportedly made without consent of adapting the famous story.
Other standouts in Herzog’s cast include Roland Topor as Dracula’s insane manservant, Renfield, and Walter Ladengast as Dr. Van Helsing, who is much more devoted to science here than in other film versions of the Bram Stoker’s story.
Murnau changed the character names for copyright reasons, and Herzog was free to use the originals: Dracula ( Klaus Kinski ), the land agent Jonathan Harker ( Bruno Ganz ), his wife Lucy ( Isabelle Adjani ), Dr. Van Helsing (Walter Ladengast), and he of the maniacal laugh, Renfield ( Roland Topor ).
And, while other versions, such as the 1931 Bela Lugosi interpretation or the 1958 Christopher Lee/Peter Cushing Horror of Dracula, have their adherents, none can match the Murnau edition for atmosphere and eerieness.
Yes, like many other Dracula movies, this one condenses and simplifies the core characters down to Jonathan Harker, Lucy, Van Helsing, Renfield and Dracula; Mina is here but as a minor character, a friend to Lucy who exists just to die.