The Empress is a member of the Vampire King's court in the Adventure Time miniseries "Stakes."
The Empress was staked by Marceline Abadeer to protect the last remaining humans.
She returned after Princess Bubblegum drained Marceline's vampire essence. She heads towards the Ice Kingdom, where she apparently mesmerizes the Ice King and gets him to deliver Finn so she can attempt to feast on his human blood after she expressed dissatisfaction with penguin blood. After Ice King has captured Finn and later Marceline, the Empress orders him to kill the latter, only for him to refuse and start an argument with her. After Finn and Marceline have freed themselves, the former distracts the Empress, allowing the latter to use the Ice King's powers to trap her in ice. Before Marceline can stake the Empress, Ice King prevents her to do so by blocking her path, but ignores the Empress' demands, eliciting her to put him deeper under her spell. However, it is later revealed that Ice King is too "thick" to be mesmerized, and is only doing her bidding because she "is a woman". The Empress then upsets the Ice King by scolding him, leading Finn to console him. After the two leave, Marceline attacks the Empress, but is quickly overwhelmed by her. However, before the Empress can hypnotize her, she is immobilized by Bubblegum, allowing Marceline to stake her and suck her soul.