Creepy Sexy

A character who, despite or precisely because being Nightmare Fuel is also greatly loved by a series' fandom, in a way. They've got it all: the eyes, the...extremities, and that sexy voice of theirs. It, even has a sexy foreign sounding name.

Typically the target of a Nightmare Fetishist. Obviously, related to Creepy Awesome and Evil Is Sexy.

See Vampires Are Sex Gods for when the creepy one just so happens to be a vampire, But Your Wings Are Beautiful for a more...'innocent' version of this trope, and see You Sexy Beast when their sexiness translates into the...bed.

Anime and Manga

 * Most monsters in Hellsing fit under this trope. ESPECIALLY Alucard. This is epitomized with the Fetish Fuel laden fight with Rip Van Rinkle.
 * Orochimaru has the ability to entice this in the fandom due to Draco in Leather Pants, and the fact that... yeah, not even going there. Where's that damn Brain Bleach when you need it.
 * The homunculus Lust is basically sex appeal incarnate. The fact that she's made from a major Eldritch Abomination and is a minor one herself (A couple thousand souls as a power core does that to ya) doesn't detract form this, and for some, it just adds to it.
 * Franken Fran.
 * Gasai Yuuno, in that creepy Yandere way.

Film

 * The Borg Queen in Star Trek: First Contact is the Trope Codifier apparently.
 * Hannibal Lecter
 * Clive Barker once noted that despite not doing "a single decent thing" during the whole franchise Pinhead gets loads and loads of fanmail from women.

Live Action Television

 * Often the actor who plays "the rapist" on daytime soaps, inevitably get the most fanmail than any other actor. Or So I Heard.

Video Games

 * Vivi from Brain Dead 13.
 * Albedo, so much Albedo. The guy likes a spot of Mind Rape, has incest issues like whoa, laughs like the extremely crazy guy he is, oh, and likes to blow his own head off to prove he can't die. And yet, there's a subsection of the fandom that finds him strangely attractive.
 * Silent Hill had this for the nurses and Pyramid Head.