Osa is the former Traveler from the territory of Zadaa and the adoptive mother of Loor. She was killed on Denduron while trying to protect Bobby and Loor from a group of attacking Bedoowan Knights. She is described by Bobby as being very beautiful, and similar in appearance to Loor. In The Merchant of Death, Osa gave Mark Dimond a Traveler ring that enabled him to receive journals from Bobby about his adventures. She is also mentioned in The Lost City of Faar, The Never War, and The Rivers of Zadaa. In the lost city of Faar Loor says that Osa had traveled to receive half of the map to Faar and then Loor gives it to Bobby and Spader.