A member of an unidentified slug-like alien race, Dolores first meets Zim and Dib when they're abducted and locked up on her planet after accidentally exposing a plot by another of her kind to infiltrate the Girly Rangers. Dolores tells Zim and Dib that whichever one of them proves to be the most heroic and worthy will be released, while the other will be executed. This leads to the two of them telling increasingly unlikely stories, making themselves look amazing and painting the other in an unflattering light.
Eventually, Dolores hears enough, and reveals that she's not actually a jailer, but a TV (or as it's called on her planet, "Shmeevee") producer. She also makes it clear that she has no intention of actually releasing either of them. Instead, she plans to keep them locked up and forced to give her stories she can use as basis for a new show.
However, the show does not appear to be successful, and Zim and Dib are soon returned to Earth in a very violent manner.