Btvs The subject of this article is non-canonical.
While created as part of licensed material, it has not been confirmed as part of the "real" Buffyverse.

Selke was a vampire and enemy of the Slayer, Buffy Summers.

In the beginning, Selke was nothing more than an average vampire who along with her coven kidnapped Willow on Halloween. Buffy saved Willow before she became a late night snack, and dusted Selke's friends. Selke was badly wounded in battle and retreated, living off rat blood for the next month. At Thanksgiving, Selke returned to exact revenge on Buffy, but in her weakened state she she was no match for Buffy and ended up getting thrown in a blazing fire. Selke somehow survived and was now more determined than ever to kill Buffy.

Selke went into hiding for months, eventually surfacing only to find that her badly burned figure scared people away. Turning to Sunnydale plastic surgeon, Doctor Flitter, Selke made him an offer to make her beautiful again in exchange for eternal life. Not able to heal her by conventional means, Flitter resorted to alchemy to restore Selke to all her nosferatu glory, creating a 'new blood' that significantly enhanced Selke. Returning to the base of operations of her coven, Selke took out the old leader Rouleau (probaly her sire), and took over the role of leader. Selke shared the same brew with her new allies, transforming the other vampires into übervamps like her.

Even with their enhanced powers, the vampires still found themselves no match for Buffy—also sparking a vampire 'civil war' as traditional vampires tried to attack the new bloods to get a taste—which caused Doctor Flitter to use his newfound talents in the dark arts to create a Dark Slayer, an evil duplicate of Buffy to take her out of the picture. Preoccupied with her plans to kill Buffy and take over Sunnydale, Selke failed to notice that her concoction was poisoned by rival vampires Spike and Drusilla, which caused her blood cells to degenerate and mutate.

During Sunnydale's Mardi Gras, Selke finally came out of hiding to kill Buffy, now transformed into a hulking ogress with brutal strength. Her transformation however slowed her down, which gave Buffy an advantage over her, and used her cunning to take Selke out for good. Selke's death triggered a chain reaction that killed all of the other vampires who drank from her brew.