Marsha Quist is the iconic villainess from 1981's classic werewolf film, The Howling.
She was played by the late Elisabeth Brooks.
Marsha is the sister of Eddie and T.C. Quist, and she is one of the werewolves residing in The Colony. She is a confessed naturist, but she is also a nymphomaniac, often flaunting her sexuality by wearing provocative leather outfits. Once Karen White and her husband, Bill Neill, arrived at The Colony (so Karen could recover from her confrontation with Eddie), the evil Marsha set her wicked sights on Bill, making several flirtatious advances towards him. She even threw herself on Bill and kissed him, only for Bill to push her away. Later in the film, however, Marsha (assumingly) attacks Bill in her werewolf form late at night.
The next night, Marsha and Bill engaged in a sexual encounter, with the full moon hovering over them. During the encounter, both Marsha and Bill transformed into werewolves, with the villainess sinking her claws in to Bill. After Karen learns what happened, Marsha stated to Karen during their confrontation that Bill is "one of us, now." In the film's climax, Marsha and the rest of The Colony's residents are locked in a barn by Karen and Chris, and the protagonists set the barn on fire. However, at the very end of the film, Marsha is revealed to have escaped the barn and survived, as she is shown at a bar ordering a hamburger; rare, of course.