The Ysanna were a race of humanoid beings inhabiting the desolate wastelands of the planet Ossus. These people, who donned tribal masks, relied on the indigenous kirruk creatures and made their homes in the nitrogen-filled valleys situated near the Eocho Mountains. Their primary sustenance came from farming, although hunting with concussion bows grew in importance. The Ysanna exhibited a degree of sensitivity to the Force, granting them the ability to manipulate the projectiles fired from their concussion bows and instilling in them a sense of responsibility to safeguard the Jedi ruins on Ossus. The Ysanna's shamans, called storm shepherds, gained the ability to foresee the planet's electrical storms. The Ysannan language was spoken by this race.
According to the tales of the Qel-Droma Epics, the Ysanna were believed to be the human Jedi survivors who lived through the Cron Supernova, an event that ravaged Ossus. It is said that the non-human survivors eventually died, leading the surviving Jedi to unite in order to endure the planet's ruined wastelands.