Looker

"You dress up as any superhero you want. Supergirl. Looker, if vampires are more your thing."

- Grace

History
At some point Looker has become a vampire and was also a superhero, who emassed a certain fandom with people who have vampires as their "thing".

Trivia

 * Much like with Supergirl it is unclear whether Looker is a fictional or real superhero in this universe.

Behind the scenes

 * In the DC Comics Looker is a superhero with psionic abilities who was also later turned into a vampire.