Le Fanu, Joseph Sheridan: Carmilla. v1. 26 Dec 07
 

Description from Wikipedia:
"Carmilla" is a Gothic novella by Joseph Sheridan Le Fanu. First published in 1872, it tells the story of a young woman's susceptibility to the attentions of a female vampire named Carmilla. "Carmilla" predates Bram Stoker's Dracula by twenty-five years, had a strong influence on Stoker's famous novel and has been adapted many times for cinema.

Carmilla, the title character, is the original prototype for a legion of female and lesbian vampires. Though Le Fanu portrays his vampire's sexuality with the circumspection that one would expect for his time, the reader can be pretty sure that lesbian attraction is the main dynamic between Carmilla and the narrator of the story.

Carmilla selected exclusively female victims, though only became emotionally involved with a few. Carmilla had nocturnal habits, but was not confined to the darkness. She had unearthly beauty and was able to change her form and to pass through solid walls. Her animal alter ego was a monstrous black cat, not a large dog as in Dracula. She did, however, sleep in a coffin.