Niki Sanders is a fictional character in the television series "Heroes". She is portrayed by actress Ali Larter. Niki is a former Las Vegas showgirl and single mother who has a rare genetic condition that causes her to have split personalities. One of these personalities, known as Jessica, is a violent and aggressive individual who often takes control of Niki's body. Over the course of the series, Niki struggles to control her split personalities and keep her family safe, while also dealing with her newfound abilities and involvement with the larger world of evolved humans. Niki is a central character in the first season of "Heroes" and remains a recurring presence throughout the rest of the series.