Wikipedia
Na'Toth is a fictional character in the universe of the science fiction television series Babylon 5. Na'Toth is the aide to Narn Ambassador G'Kar, one of the main characters of the series. She appears mainly in the first and second seasons, with a final appearance in the fifth season.
She was played by Julie Caitlin Brown in the first season (a last-minute casting change after Susan Kellerman walked off the set). Due to problems with the extensive makeup and prosthetics required to turn her into a Narn, Brown did not reprise her role for the second season of the series; similar problems had caused the departure of Susan Kellerman and, earlier, of Mary Woronov as Ko'Dath, who was to have been a regular character. For the second season, Brown was replaced by Mary Kay Adams. Executive producer J. Michael Straczynski quickly became dissatisfied with Adams' more understated approach to the role, and Na'Toth was written out of the series after appearing in two more episodes. Brown returned to reprise the role in the fifth-season episode " A Tragedy of Telepaths".
In The Babylon Files, a Babylon 5 guidebook, series creator Straczynski said he had considered having G'Kar have a "revolving-door" series of aides, akin to Murphy Brown.