Mitena Haro was the assumed name of an alien in the guise of a Bolian female. The unnamed alien species kidnapped Captain Jean-Luc Picard, a Mizarian named Kova Tholl, and a Chalnoth named Esoqq, as part of a maze experiment to study the nature of authority.
While in disguise as Haro, the alien claimed to be a first year cadet at Starfleet Academy. She also stated her best area of study to be impulse propulsion systems, with a particular interest in field coils. She followed Picard's orders and worked with the others in opening the door. She also contributed to suspicion that Tholl might be working with the captors, but defended Picard when he was accused.
She blew her cover by mentioning his mission to Mintaka III and the Phyrox plague eradication, events which were unlikely and impossible for her, respectively, to know. When Picard confronted her, she turned back into her native form. (TNG: "Allegiance")