Abigail "Abby" Sciuto is a fictional character from the NCIS television series on CBS Television, and is portrayed by Pauley Perrette. In a season 10 episode entitled "Hit and Run", a young Abby was played by Brighton Sharbino in flashbacks. Like Jethro Gibbs, Anthony DiNozzo, and Dr. Donald Mallard, Abby was introduced in the episodes "Ice Queen" and "Meltdown" of the television show JAG (which together served as the backdoor pilot for NCIS), and has appeared in every episode of NCIS, in addition to being featured on the show's spin-offs, NCIS: Los Angeles (two episodes) and NCIS: New Orleans (two episodes). The role has made Perrette one of the most popular actresses on U.S. primetime television in 2011, according to Q Score.
Abby is a forensic scientist at the Naval Criminal Investigative Service headquarters at the Washington Navy Yard, with expertise in ballistics, digital forensics, and DNA analysis. In the first episode of the seventh season, "Truth or Consequences", DiNozzo, while under the influence of a truth serum, describes her as "a paradox wrapped in an oxymoron smothered in contradictions in terms. Sleeps in a coffin. Really, the happiest Goth you'll ever meet." Her gothic style of dress and her interest in death and the supernatural contrast with her generally hyperactive demeanor and enthusiasm about her work.
Source: Wikipedia, "Abby Sciuto", available under the CC-BY-SA License.