Mitena Haro was the assumed name of an alien in the guise of a Bolian female. The unnamed alien race kidnapped Captain Jean-Luc Picard, a Mizarian named Kova Tholl, and a Chalnoth named Esoqq, as part of an experiment. They, a telepathically linked race, wanted to study the nature of authority, as the concept had formerly been unknown to them, as they were all identical. See TNG episode Allegiance.
As "Mitena Haro", the alien claimed to be a first year cadet of Starfleet Academy, "one of three" Bolians in the whole Academy. She also stated her best area of study to be impulse propulsion systems, futher commenting that she is "really good with field coils".
She was played by Joycelyn O'Brien.
Uncertainties
The episode Allegiance did not make it clear if the aliens had copied a real Mitena Haro, or if she was completely made up by them.
Most Bolians are seen to be bald, including women and children. Mitena was shown with greyish hair. She is one of two Bolian women seen with hair, including an extra sitting in Ten Forward in episode Ménage à Troi. The fact that this particular Bolian is fake does not explain away her hair, as it is assumed that Picard would know whether or not the well established Bolian race has hair. Popular fan theories regarding Bolian hair include the possiblity that human-Bolian hybrids may have hair, and that it may simply be fashionable among some Bolians to wear wigs. This latter theory is bolstered by the Deep Space 9 episode The Muse, in which Jake Sisko sees a Bolian wearing an obvious toupee on the promenade deck. This theory might go a long way toward explaining the career choice of Mr. Mot, the Enterprise-D's Bolian barber.