Stirba is a 10,000-year-old werewolf sorceress and the evil queen of all werewolves. She had become an aged, old crone by the time of the film's events, but in her first appearance in the film, Stirba regained her youth and beauty in a ritual that included lamb's blood and a sacrifice of a young woman. After this, Stirba engaged in sexual tryst with her minions Mariana and Vlad, while all three were in partial werewolf form.
Stirba focused on her evil mission, which was to take down her brother, Stefan Crosscoe, and anyone else in her way. Later in the film, the evil Stirba cast her spell that turned Mariana and Vlad into werewolves, while also killing Vasile, a Romanian dwarf helping Stefan, Ben White, and Jenny Templeton. Vasile had been wearing protective ear plugs to prevent Stirba's spells from affecting him, but once they were dropped, her powerful voice caused Vasile's eyeballs to explode. After killing Vasile, Stirba also captured Jenny, leading to Ben and Stefan returning to her castle to rescue her. Stefan confronted his evil sister for the final time, as he cast a spell that later killed not only himself, but the villainess as well.
- Sybil Danning appeared as Brenda in the 1980 Italian detective thriller "Day of the Cobra".
- Sybil Danning earlier appeard as the evil sorceress Ariadne , in the 1983 Italian adventure film, "Hercules".
- Sybil Danning appeared as Angel in the 1984 action film "Jungle Warriors".
- Sybil Danning appeared as Mary Kruger in the 1984 episode "Visitor's Choice" for the TV series "V".
- Sybil Danning appeared as Warden Sutter in the 1986 film "Refor School Girls".
- Sybil Danning apperead as The Alien Queen in the 1988 film, "The Phantom Empire".
- Sybil Danning later appeared as evil succubus Pamela Dare in the 1989 episode "Succubus" in the TV series Superboy.