There is comedy, and then there is dark comedy, and then there is Julia Davis’s comedy.

The British actress creates and stars in series in which people are either predator or prey. Her shows are essentially social-comedy horror stories, and Davis likes to play the monsters: emotional parasites who worm into other people’s lives and devour them from the inside out.

In the laceratingly funny “Nighty Night,” she played a beautician seeking a replacement for her cancer-stricken husband while he was still alive. In “Hunderby,” a Gothic melodrama parody, she was a housekeeper out to undermine the marriage of the minister she worked for. In “Camping” — whose American adaptation is now on HBO — she was the libidinous outsider who upended an outdoorsy group vacation.

It’s not pretty, but in Davisworld, that’s life. It’s awful, in the best way.

In “Sally4Ever,” a British coproduction beginning Sunday on HBO (and paired with “Camping”), Davis does not have the title role. That unfortunate is Sally (Catherine Shepherd) a marketing executive living a life of quiet dissatisfaction with David (Alex Macqueen), her boyfriend of 10 years and a simpering milquetoast, heavy on the milque.

Sally’s life is like a picture-dictionary definition of “settling.” She sleepwalks through her days at her stultifying office, busy with a campaign to “put the sexy back in eggs.” She has dull meals and boring sex with David. She seems quietly horrified by her life, as if she’s just resigned herself to get from here to the grave with a minimum of fuss.