She is voluptuous, promiscuous and just plain venomous. She is the vixen, a character long familiar to moviegoers and soap opera addicts. Yet never before this year has she appeaed in such variety — and with such energy –on prime-time TV.

Take Abby Cunningham — please. The suburban vamp of CBS’s Knots Landing so far has had an affair with Richard Avery, one of the husbands on the cul-de-sac; gotten another husband, Gary Ewing, into trouble; stolen her brother Sid Fairgate’s invention; and gone to bed (between satin sheets) with J.R., up from Dallas to wreak some havoc in California.

Indeed, what ‘s so surprising about this year’s profusion of prime-time viragoes is not the hostility they have evoked, but the excitement they have engendered. The classics like Gone with the Wind and daytime soaps like Search for Tomorrow has become, in the evening hours, the role model many people, especially women, would like to emulate. One obvious reason for this turnabout has been the success of CBS’s Dallas, a breeding ground for glamorous but treacherous women. In addition to Sue Ellen, the perfect Texas wife truned alcoholic tramp, and her slithery baby sister Kristin, who tried to kill J.R., Dallas has now given us the unscrupulous Leslie Stewart, J.R.’s personal public-relations consultant. Leslie is so flagrantly unethical that the Public Relations Society of America has felt called upon to protest her character and condemn her conduct. Yet, to hear such shady ladies discussed by the producers who created them and the actresses who animate them, you’d think vice was a virtue.

Donna Mills, who plays the sex-crazed Abby on Knots Landing , says: “I think characters like Abby and J.R. are popular because they act out a lot of people’s fantasies. I know that I’d like to do some of the things that Abby does. Our instincts aren’t that far apart. The only differences is that I have a conscience and morals that she doesn’t have.” Donna Mills says, “I guess once a victim, always a victim. Once you’re typecast in this town, it’s difficult to break that image.” A petite blonde in her middle 30s, with the lithe figure of a ballerina(which she once was), Donna started out in television on soap operas. In 1971, she went to California to play Clint Eastwood’s girl friend in his film, “Play Misty for Me.” She spent a good part of the next few years being chased across the screen. “I was bored playing the virtuous but vulnerable woman who was pursued by villains all the time. It was not the way I wanted to spend the rest of my life.” So Donna decided to turn down all the victim roles offered her.

For the next year and a half she played a lot of tennis. Then she heard about the role of Abby Cunningham and decided to go after it. “The day after she came in to see me about the role,” recalls David Jacobs, the creator of both Dallas and Knots Landing, “she called back and said she wanted to read for it, which was extraordinary for someone of her experience. She said she was afraid that we were dismissing her, and the truth of it is, we were. My initial impression was that she was too sweet, I guess because she had played sweet and victim so much of the time.” Donna’s reading and her pursuit of the role convinced Jacobs and the other producers of the show that she had a harder edge than they had first imagined. She has been stirring up trouble ever since.

“I love this character,” Donna says. “I love her naughtiness, her open sexuality and her intelligence. After all those years of playing the victims and fugitives, I enjoy playing the aggressor. It’s much more fun to make things happen than to have them happen to you. People come up to me and say, “You’ve added so much spice to the show. I can’t wait to see what you do next’.” One of Donna’s ambitions, of which Abby would certainly approve, is to produce her own films. The opportunity to be devious and ruthless, after years of being virtuous and sweet, may at last have given Donna the power to realize her dreams.