Nsob was a robot aboard the starship that Nävis was on when she crashlanded on the jungle planet. He managed to take the infant out of her cryo-sleep chamber and into a smaller vessel which he used to land safely on the surface.
He ended up raising young Nävis and her Tigrours friend, Houyo, until his destruction by a malignant mechanical entity. An electric shock Nävis received during the fight with that being caused her to forget everything that happened before. Her memories of Nsob were restored many years later when she returned to the planet to bring Heiliig back to his people.